Treat header as first paragraph for shortened markdown descriptions
"The Rust Standard LibraryThe Rust Standard Library is the …" is an awful description.
Do not attempt to unlock envlock in child process after a fork.
This implements the first two points from https://github.com/rust-lang/rust/issues/64718#issuecomment-793030479
This is a breaking change for cases where the environment is accessed in a Command::pre_exec closure. Except for single-threaded programs these uses were not correct anyway since they aren't async-signal safe.
Note that we had a ui test that explicitly tried `env::set_var` in `pre_exec`. As expected it failed with these changes when I tested locally.
WASI: Switch to crt1-command.o to enable support for new-style commands
This switches Rust's WASI target to use crt1-command.o instead of
crt1.o, which enables support for new-style commands. By default,
new-style commands work the same way as old-style commands, so nothing
immediately changes here, but this will be needed by later changes to
enable support for typed arguments.
See here for more information on new-style commands:
- https://github.com/WebAssembly/wasi-libc/pull/203
- https://reviews.llvm.org/D81689
r? ```@alexcrichton```
rustdoc: Remove redundant enableSearchInput function
enableSearchInput was called from two places:
- setupSearchLoader
- addSearchOptions, which is itself called from setupSearchLoader only
This commit can safely get rid of the addSearchOptions calls entirely, and since the setupSearchLoader call is immediately preceded by other method calls on search_input, there's no need to check if it's set.
Edition-specific preludes
This changes `{std,core}::prelude` to export edition-specific preludes under `rust_2015`, `rust_2018` and `rust_2021`. (As suggested in https://github.com/rust-lang/rust/issues/51418#issuecomment-395630382.) For now they all just re-export `v1::*`, but this allows us to add things to the 2021edition prelude soon.
This also changes the compiler to make the automatically injected prelude import dependent on the selected edition.
cc `@rust-lang/libs` `@djc`
Implement RFC 2945: "C-unwind" ABI
## Implement RFC 2945: "C-unwind" ABI
This branch implements [RFC 2945]. The tracking issue for this RFC is #74990.
The feature gate for the issue is `#![feature(c_unwind)]`.
This RFC was created as part of the ffi-unwind project group tracked at rust-lang/lang-team#19.
### Changes
Further details will be provided in commit messages, but a high-level overview
of the changes follows:
* A boolean `unwind` payload is added to the `C`, `System`, `Stdcall`,
and `Thiscall` variants, marking whether unwinding across FFI boundaries is
acceptable. The cases where each of these variants' `unwind` member is true
correspond with the `C-unwind`, `system-unwind`, `stdcall-unwind`, and
`thiscall-unwind` ABI strings introduced in RFC 2945 [3].
* This commit adds a `c_unwind` feature gate for the new ABI strings.
Tests for this feature gate are included in `src/test/ui/c-unwind/`, which
ensure that this feature gate works correctly for each of the new ABIs.
A new language features entry in the unstable book is added as well.
* We adjust the `rustc_middle::ty::layout::fn_can_unwind` function,
used to compute whether or not a `FnAbi` object represents a function that
should be able to unwind when `panic=unwind` is in use.
* Changes are also made to
`rustc_mir_build::build::should_abort_on_panic` so that the function ABI is
used to determind whether it should abort, assuming that the `panic=unwind`
strategy is being used, and no explicit unwind attribute was provided.
[RFC 2945]: https://github.com/rust-lang/rfcs/blob/master/text/2945-c-unwind-abi.md
Implement RFC 2945: "C-unwind" ABI
## Implement RFC 2945: "C-unwind" ABI
This branch implements [RFC 2945]. The tracking issue for this RFC is #74990.
The feature gate for the issue is `#![feature(c_unwind)]`.
This RFC was created as part of the ffi-unwind project group tracked at rust-lang/lang-team#19.
### Changes
Further details will be provided in commit messages, but a high-level overview
of the changes follows:
* A boolean `unwind` payload is added to the `C`, `System`, `Stdcall`,
and `Thiscall` variants, marking whether unwinding across FFI boundaries is
acceptable. The cases where each of these variants' `unwind` member is true
correspond with the `C-unwind`, `system-unwind`, `stdcall-unwind`, and
`thiscall-unwind` ABI strings introduced in RFC 2945 [3].
* This commit adds a `c_unwind` feature gate for the new ABI strings.
Tests for this feature gate are included in `src/test/ui/c-unwind/`, which
ensure that this feature gate works correctly for each of the new ABIs.
A new language features entry in the unstable book is added as well.
* We adjust the `rustc_middle::ty::layout::fn_can_unwind` function,
used to compute whether or not a `FnAbi` object represents a function that
should be able to unwind when `panic=unwind` is in use.
* Changes are also made to
`rustc_mir_build::build::should_abort_on_panic` so that the function ABI is
used to determind whether it should abort, assuming that the `panic=unwind`
strategy is being used, and no explicit unwind attribute was provided.
[RFC 2945]: https://github.com/rust-lang/rfcs/blob/master/text/2945-c-unwind-abi.md
Fix false positives on procedural macros of `missing_inline_in_public_items` lint
Fixes#6486.
changelog: Fix false positives on procedural macros of `missing_inline_in_public_items` lint.
Improve needless_borrowed_ref docs
changelog: none
I think "borrowed ref" is a confusing description for this lint. Destructuring a reference is the opposite of borrowing. So I updated the wording throughout the docs. Unfortunately this nit applies to the name of the lint itself, but I won't bother changing that. One motivation for these changes is to clarify the difference between this lint and `needless_borrow` (they are actually quite different). Let me know if I need to clarify anything or if you disagree with any changes.
Remove the -Zinsert-sideeffect
This removes all of the code we had in place to work-around LLVM's
handling of forward progress. From this removal excluded is a workaround
where we'd insert a `sideeffect` into clearly infinite loops such as
`loop {}`. This code remains conditionally effective when the LLVM
version is earlier than 12.0, which fixed the forward progress related
miscompilations at their root.
This removes all of the code we had in place to work-around LLVM's
handling of forward progress. From this removal excluded is a workaround
where we'd insert a `sideeffect` into clearly infinite loops such as
`loop {}`. This code remains conditionally effective when the LLVM
version is earlier than 12.0, which fixed the forward progress related
miscompilations at their root.
Store HIR attributes in a side table
Same idea as #72015 but for attributes.
The objective is to reduce incr-comp invalidations due to modified attributes.
Notably, those due to modified doc comments.
Implementation:
- collect attributes during AST->HIR lowering, in `LocalDefId -> ItemLocalId -> &[Attributes]` nested tables;
- access the attributes through a `hir_owner_attrs` query;
- local refactorings to use this access;
- remove `attrs` from HIR data structures one-by-one.
Change in behaviour:
- the HIR visitor traverses all attributes at once instead of parent-by-parent;
- attribute arrays are sometimes duplicated: for statements and variant constructors;
- as a consequence, attributes are marked as used after unused-attribute lint emission to avoid duplicate lints.
~~Current bug: the lint level is not correctly applied in `std::backtrace_rs`, triggering an unused attribute warning on `#![no_std]`. I welcome suggestions.~~
Store HIR attributes in a side table
Same idea as #72015 but for attributes.
The objective is to reduce incr-comp invalidations due to modified attributes.
Notably, those due to modified doc comments.
Implementation:
- collect attributes during AST->HIR lowering, in `LocalDefId -> ItemLocalId -> &[Attributes]` nested tables;
- access the attributes through a `hir_owner_attrs` query;
- local refactorings to use this access;
- remove `attrs` from HIR data structures one-by-one.
Change in behaviour:
- the HIR visitor traverses all attributes at once instead of parent-by-parent;
- attribute arrays are sometimes duplicated: for statements and variant constructors;
- as a consequence, attributes are marked as used after unused-attribute lint emission to avoid duplicate lints.
~~Current bug: the lint level is not correctly applied in `std::backtrace_rs`, triggering an unused attribute warning on `#![no_std]`. I welcome suggestions.~~
Previously, `masked_crates` existed both on `Cache` and on
`clean::Crate`. During cache population, the `clean::Crate` version was
`take`n and moved to `Cache`.
This change removes the version on `clean::Crate` and instead directly
mutates `Cache.masked_crates` to initialize it. This has the advantage
of avoiding duplication and avoiding unnecessary allocation, as well as
making the flow of information through rustdoc less confusing.
The one downside I see is that `clean::utils::krate()` now uses the side
effect of mutating `DocContext.cache` instead of returning the data
directly, but it already mutated the `Cache` for other things (e.g.,
`deref_trait_did`) so it's not really new behavior. Also,
`clean::utils::krate()` is only called once (and is meant to only be
called once since it performs expensive and potentially destructive
operations) so the mutation shouldn't be an issue.
RFC 1240 states that it is unsafe to capture references into a
packed-struct. This PR ensures that when a closure captures a precise
path, we aren't violating this safety constraint.
To acheive so we restrict the capture precision to the struct itself.
An interesting edge case:
```rust
struct Foo(String);
let foo: Foo;
let c = || {
println!("{}", foo.0);
let x = foo.0;
}
```
Given how closures get desugared today, foo.0 will be moved into the
closure, making the `println!`, safe. However this can be very subtle
and also will be unsafe if the closure gets inline.
Closes: https://github.com/rust-lang/project-rfc-2229/issues/33
Don't hardcode the `v1` prelude in diagnostics, to allow for new preludes.
Instead of looking for `std::prelude::v1`, this changes the two places where that was hardcoded to look for `std::prelude::<anything>` instead.
This is needed for https://github.com/rust-lang/rust/pull/82217.
r? `@estebank`
Bump tracing-tree dependency
This bump fixes two small rendering things that were annoying me:
* The first level didn't have an opening line
* When wraparound happens, there was no warning, the levels just disappeared. Now there is a line that shows that wraparound is happening
See https://github.com/davidbarsky/tracing-tree/pull/31/files for how the look changes
Update README.md to use the correct cmake version number
LLVM requires at least cmake 3.13.4 and cmake is only required to build
LLVM.
https://www.llvm.org/docs/CMake.html
Also closes#42555
Add Option::get_or_default
Tracking issue: #82901
The original issue is #55042, which was closed, but for an invalid reason (see discussion there). Opening this to reconsider (I hope that's okay). It seems like the only gap for `Option` being "entry-like".
I ran into a need for this method where I had a `Vec<Option<MyData>>` and wanted to do `vec[n].get_or_default().my_data_method()`. Using an `Option` as an inner component of a data structure is probably where the need for this will normally arise.
Build rustdoc for run-make tests, not just run-make-fulldeps
Rustdoc almost never needs a full stage 2 compiler, and requiring
rustdoc tests to be in run-make-fulldeps adds a lot of compile time for
no reason.
This is the same change from https://github.com/rust-lang/rust/pull/81197, but separated into its own PR. I ran into this again today while working on https://github.com/rust-lang/docs.rs/issues/1302.
r? ```@Mark-Simulacrum```
Fixes to ExitStatus and its docs
* On Unix, properly display every possible wait status (and don't panic on weird values)
* In the documentation, be clear and consistent about "exit status" vs "wait status".
Stabilize `unsafe_op_in_unsafe_fn` lint
This makes it possible to override the level of the `unsafe_op_in_unsafe_fn`, as proposed in https://github.com/rust-lang/rust/issues/71668#issuecomment-729770896.
Tracking issue: #71668
r? ```@nikomatsakis``` cc ```@SimonSapin``` ```@RalfJung```
# Stabilization report
This is a stabilization report for `#![feature(unsafe_block_in_unsafe_fn)]`.
## Summary
Currently, the body of unsafe functions is an unsafe block, i.e. you can perform unsafe operations inside.
The `unsafe_op_in_unsafe_fn` lint, stabilized here, can be used to change this behavior, so performing unsafe operations in unsafe functions requires an unsafe block.
For now, the lint is allow-by-default, which means that this PR does not change anything without overriding the lint level.
For more information, see [RFC 2585](https://github.com/rust-lang/rfcs/blob/master/text/2585-unsafe-block-in-unsafe-fn.md)
### Example
```rust
// An `unsafe fn` for demonstration purposes.
// Calling this is an unsafe operation.
unsafe fn unsf() {}
// #[allow(unsafe_op_in_unsafe_fn)] by default,
// the behavior of `unsafe fn` is unchanged
unsafe fn allowed() {
// Here, no `unsafe` block is needed to
// perform unsafe operations...
unsf();
// ...and any `unsafe` block is considered
// unused and is warned on by the compiler.
unsafe {
unsf();
}
}
#[warn(unsafe_op_in_unsafe_fn)]
unsafe fn warned() {
// Removing this `unsafe` block will
// cause the compiler to emit a warning.
// (Also, no "unused unsafe" warning will be emitted here.)
unsafe {
unsf();
}
}
#[deny(unsafe_op_in_unsafe_fn)]
unsafe fn denied() {
// Removing this `unsafe` block will
// cause a compilation error.
// (Also, no "unused unsafe" warning will be emitted here.)
unsafe {
unsf();
}
}
```
This is a breaking change for cases where the environment is
accessed in a Command::pre_exec closure. Except for
single-threaded programs these uses were not correct
anyway since they aren't async-signal safe.
It's possible to create a deadlock with stdin/stdout I/O on a single thread:
* the child process may fill its stdout buffer, and have to wait for the parent process to read it,
* but the parent process may be waiting until its stdin write finishes before reading the stdout.
Therefore, the parent process should use separate threads for writing and reading.
