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stabilize shorter-tail-lifetimes

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This commit is contained in:
Ding Xiang Fei 2024-10-21 04:47:02 +08:00
parent be01dabfef
commit 0689b2139f
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GPG Key ID: 3CD748647EEF6359
18 changed files with 39 additions and 46 deletions
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2
compiler/rustc_feature/src/accepted.rs
View File

@ -364,6 +364,8 @@ macro_rules! declare_features {
(accepted, self_in_typedefs, "1.32.0", Some(49303)),
/// Allows `Self` struct constructor (RFC 2302).
(accepted, self_struct_ctor, "1.32.0", Some(51994)),
/// Shortern the tail expression lifetime
(accepted, shorter_tail_lifetimes, "CURRENT_RUSTC_VERSION", Some(123739)),
/// Allows using subslice patterns, `[a, .., b]` and `[a, xs @ .., b]`.
(accepted, slice_patterns, "1.42.0", Some(62254)),
/// Allows use of `&foo[a..b]` as a slicing syntax.

2
compiler/rustc_feature/src/unstable.rs
View File

@ -571,8 +571,6 @@ pub fn internal(&self, feature: Symbol) -> bool {
(unstable, rust_cold_cc, "1.63.0", Some(97544)),
/// Allows use of x86 SHA512, SM3 and SM4 target-features and intrinsics
(unstable, sha512_sm_x86, "1.82.0", Some(126624)),
/// Shortern the tail expression lifetime
(unstable, shorter_tail_lifetimes, "1.79.0", Some(123739)),
/// Allows the use of SIMD types in functions declared in `extern` blocks.
(unstable, simd_ffi, "1.0.0", Some(27731)),
/// Allows specialization of implementations (RFC 1210).

4
compiler/rustc_hir_analysis/src/check/region.rs
View File

@ -167,9 +167,7 @@ fn resolve_block<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, blk: &'tcx h
}
}
if let Some(tail_expr) = blk.expr {
if visitor.tcx.features().shorter_tail_lifetimes()
&& blk.span.edition().at_least_rust_2024()
{
if blk.span.edition().at_least_rust_2024() {
visitor.terminating_scopes.insert(tail_expr.hir_id.local_id);
}
visitor.visit_expr(tail_expr);

23
compiler/rustc_lint/src/tail_expr_drop_order.rs
View File

@ -14,15 +14,14 @@
use crate::{LateContext, LateLintPass};
declare_lint! {
/// The `tail_expr_drop_order` lint looks for those values generated at the tail expression location, that of type
/// with a significant `Drop` implementation, such as locks.
/// In case there are also local variables of type with significant `Drop` implementation as well,
/// this lint warns you of a potential transposition in the drop order.
/// Your discretion on the new drop order introduced by Edition 2024 is required.
/// The `tail_expr_drop_order` lint looks for those values generated at the tail expression location,
/// that runs a custom `Drop` destructor.
/// Some of them may be dropped earlier in Edition 2024 that they used to in Edition 2021 and prior.
/// This lint detects those cases and provides you information on those values and their custom destructor implementations.
/// Your discretion on this information is required.
///
/// ### Example
/// ```rust,edition2024
/// #![feature(shorter_tail_lifetimes)]
/// ```rust,edition2021
/// #![warn(tail_expr_drop_order)]
/// struct Droppy(i32);
/// impl Droppy {
@ -37,12 +36,12 @@
/// println!("loud drop {}", self.0);
/// }
/// }
/// fn edition_2024() -> i32 {
/// fn edition_2021() -> i32 {
/// let another_droppy = Droppy(0);
/// Droppy(1).get()
/// }
/// fn main() {
/// edition_2024();
/// edition_2021();
/// }
/// ```
///
@ -137,7 +136,7 @@ fn check_fn(
_: Span,
def_id: rustc_span::def_id::LocalDefId,
) {
if cx.tcx.sess.at_least_rust_2024() && cx.tcx.features().shorter_tail_lifetimes() {
if !body.value.span.edition().at_least_rust_2024() {
Self::check_fn_or_closure(cx, fn_kind, body, def_id);
}
}
@ -185,8 +184,8 @@ fn visit_local(&mut self, local: &'tcx LetStmt<'tcx>) {
impl<'a, 'tcx> LintVisitor<'a, 'tcx> {
fn check_block_inner(&mut self, block: &Block<'tcx>) {
if !block.span.at_least_rust_2024() {
// We only lint for Edition 2024 onwards
if block.span.at_least_rust_2024() {
// We only lint up to Edition 2021
return;
}
let Some(tail_expr) = block.expr else { return };

12
tests/ui/drop/drop_order.rs
View File

@ -105,6 +105,7 @@ fn match_(&self) {
() => self.print(10),
}
#[cfg(edition2021)]
match {
match self.option_loud_drop(14) {
_ => {
@ -115,6 +116,17 @@ fn match_(&self) {
} {
_ => self.print(12),
}
#[cfg(edition2024)]
match {
match self.option_loud_drop(12) {
_ => {
self.print(11);
self.option_loud_drop(14)
}
}
} {
_ => self.print(13),
}
match {
loop {

12
tests/ui/drop/lint-tail-expr-drop-order-gated.rs
View File

@ -1,15 +1,11 @@
// This test ensures that `tail_expr_drop_order` does not activate in case Edition 2024 is not used
// or the feature gate `shorter_tail_lifetimes` is disabled.
// This test is to demonstrate that the lint is gated behind Edition and
// is triggered only for Edition 2021 and before.
//@ revisions: neither no_feature_gate edition_less_than_2024
//@ check-pass
//@ [neither] edition: 2021
//@ [no_feature_gate] compile-flags: -Z unstable-options
//@ [no_feature_gate] edition: 2024
//@ [edition_less_than_2024] edition: 2021
//@ edition: 2024
//@ compile-flags: -Z unstable-options
#![deny(tail_expr_drop_order)]
#![cfg_attr(edition_less_than_2024, feature(shorter_tail_lifetimes))]
struct LoudDropper;
impl Drop for LoudDropper {

4
tests/ui/drop/lint-tail-expr-drop-order.rs
View File

@ -1,12 +1,10 @@
//@ compile-flags: -Z unstable-options
//@ edition: 2024
//@ edition: 2021
// Edition 2024 lint for change in drop order at tail expression
// This lint is to capture potential change in program semantics
// due to implementation of RFC 3606 <https://github.com/rust-lang/rfcs/pull/3606>
#![deny(tail_expr_drop_order)]
#![feature(shorter_tail_lifetimes)]
struct LoudDropper;
impl Drop for LoudDropper {

8
tests/ui/drop/lint-tail-expr-drop-order.stderr
View File

@ -1,5 +1,5 @@
error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
--> $DIR/lint-tail-expr-drop-order.rs:29:15
--> $DIR/lint-tail-expr-drop-order.rs:27:15
|
LL | let x = LoudDropper;
| - these values have significant drop implementation and will observe changes in drop order under Edition 2024
@ -10,13 +10,13 @@ LL | x.get() + LoudDropper.get()
= warning: this changes meaning in Rust 2024
= note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
note: the lint level is defined here
--> $DIR/lint-tail-expr-drop-order.rs:8:9
--> $DIR/lint-tail-expr-drop-order.rs:7:9
|
LL | #![deny(tail_expr_drop_order)]
| ^^^^^^^^^^^^^^^^^^^^
error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
--> $DIR/lint-tail-expr-drop-order.rs:36:23
--> $DIR/lint-tail-expr-drop-order.rs:34:23
|
LL | let x = LoudDropper;
| - these values have significant drop implementation and will observe changes in drop order under Edition 2024
@ -27,7 +27,7 @@ LL | move || x.get() + LoudDropper.get()
= note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
--> $DIR/lint-tail-expr-drop-order.rs:65:19
--> $DIR/lint-tail-expr-drop-order.rs:63:19
|
LL | let x = LoudDropper;
| - these values have significant drop implementation and will observe changes in drop order under Edition 2024

2
tests/ui/drop/tail-expr-drop-order-negative.edition2024.stderr
View File

@ -1,5 +1,5 @@
error[E0716]: temporary value dropped while borrowed
--> $DIR/tail-expr-drop-order-negative.rs:11:15
--> $DIR/tail-expr-drop-order-negative.rs:9:15
|
LL | x.replace(std::cell::RefCell::new(123).borrow()).is_some()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - temporary value is freed at the end of this statement

2
tests/ui/drop/tail-expr-drop-order-negative.rs
View File

@ -3,8 +3,6 @@
//@ [edition2024] edition: 2024
//@ [edition2021] check-pass
#![feature(shorter_tail_lifetimes)]
fn why_would_you_do_this() -> bool {
let mut x = None;
// Make a temporary `RefCell` and put a `Ref` that borrows it in `x`.

1
tests/ui/drop/tail-expr-drop-order.rs
View File

@ -4,7 +4,6 @@
//@ edition: 2024
//@ run-pass
#![feature(shorter_tail_lifetimes)]
#![allow(unused_imports)]
#![allow(dead_code)]
#![allow(unused_variables)]

2
tests/ui/lifetimes/refcell-in-tail-expr.edition2021.stderr
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@ -1,5 +1,5 @@
error[E0597]: `cell` does not live long enough
--> $DIR/refcell-in-tail-expr.rs:12:27
--> $DIR/refcell-in-tail-expr.rs:10:27
|
LL | let cell = std::cell::RefCell::new(0u8);
| ---- binding `cell` declared here

2
tests/ui/lifetimes/refcell-in-tail-expr.rs
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@ -4,8 +4,6 @@
//@ [edition2024] compile-flags: -Zunstable-options
//@ [edition2024] check-pass
#![cfg_attr(edition2024, feature(shorter_tail_lifetimes))]
fn main() {
let cell = std::cell::RefCell::new(0u8);

2
tests/ui/lifetimes/shorter-tail-expr-lifetime.edition2021.stderr
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@ -1,5 +1,5 @@
error[E0597]: `c` does not live long enough
--> $DIR/shorter-tail-expr-lifetime.rs:10:5
--> $DIR/shorter-tail-expr-lifetime.rs:8:5
|
LL | let c = std::cell::RefCell::new("..");
| - binding `c` declared here

2
tests/ui/lifetimes/shorter-tail-expr-lifetime.rs
View File

@ -3,8 +3,6 @@
//@ [edition2024] edition: 2024
//@ [edition2024] run-pass
#![cfg_attr(edition2024, feature(shorter_tail_lifetimes))]
fn f() -> usize {
let c = std::cell::RefCell::new("..");
c.borrow().len() //[edition2021]~ ERROR: `c` does not live long enough

2
tests/ui/lifetimes/tail-expr-in-nested-expr.rs
View File

@ -1,8 +1,6 @@
//@ edition: 2024
//@ compile-flags: -Zunstable-options
#![feature(shorter_tail_lifetimes)]
fn main() {
let _ = { String::new().as_str() }.len();
//~^ ERROR temporary value dropped while borrowed

2
tests/ui/lifetimes/tail-expr-in-nested-expr.stderr
View File

@ -1,5 +1,5 @@
error[E0716]: temporary value dropped while borrowed
--> $DIR/tail-expr-in-nested-expr.rs:7:15
--> $DIR/tail-expr-in-nested-expr.rs:5:15
|
LL | let _ = { String::new().as_str() }.len();
| ^^^^^^^^^^^^^---------

1
tests/ui/lifetimes/tail-expr-lock-poisoning.rs
View File

@ -4,7 +4,6 @@
//@ [edition2024] edition: 2024
//@ run-pass
//@ needs-unwind
#![cfg_attr(edition2024, feature(shorter_tail_lifetimes))]
use std::sync::Mutex;