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Stabilize move_ref_pattern
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@Amjad50
Amjad50 committed Sep 15, 2020
1 parent 715e934 commit da700cb
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Showing 49 changed files with 271 additions and 492 deletions.
3 changes: 3 additions & 0 deletions compiler/rustc_feature/src/accepted.rs
View file
Expand Up @@ -270,6 +270,9 @@ declare_features! (
(accepted, track_caller, "1.46.0", Some(47809), None),
/// Allows `#[doc(alias = "...")]`.
(accepted, doc_alias, "1.48.0", Some(50146), None),
/// Allows patterns with concurrent by-move and by-ref bindings.
/// For example, you can write `Foo(a, ref b)` where `a` is by-move and `b` is by-ref.
(accepted, move_ref_pattern, "1.48.0", Some(68354), None),

// -------------------------------------------------------------------------
// feature-group-end: accepted features
Expand Down
4 changes: 0 additions & 4 deletions compiler/rustc_feature/src/active.rs
View file
Expand Up @@ -527,10 +527,6 @@ declare_features! (
/// For example, you can write `x @ Some(y)`.
(active, bindings_after_at, "1.41.0", Some(65490), None),

/// Allows patterns with concurrent by-move and by-ref bindings.
/// For example, you can write `Foo(a, ref b)` where `a` is by-move and `b` is by-ref.
(active, move_ref_pattern, "1.42.0", Some(68354), None),

/// Allows `impl const Trait for T` syntax.
(active, const_trait_impl, "1.42.0", Some(67792), None),

Expand Down
70 changes: 4 additions & 66 deletions compiler/rustc_mir_build/src/thir/pattern/check_match.rs
View file
Expand Up @@ -71,13 +71,13 @@ impl<'tcx> Visitor<'tcx> for MatchVisitor<'_, 'tcx> {
hir::LocalSource::AwaitDesugar => ("`await` future binding", None),
};
self.check_irrefutable(&loc.pat, msg, sp);
self.check_patterns(false, &loc.pat);
self.check_patterns(&loc.pat);
}

fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) {
intravisit::walk_param(self, param);
self.check_irrefutable(&param.pat, "function argument", None);
self.check_patterns(false, &param.pat);
self.check_patterns(&param.pat);
}
}

Expand Down Expand Up @@ -119,10 +119,7 @@ impl PatCtxt<'_, '_> {
}

impl<'tcx> MatchVisitor<'_, 'tcx> {
fn check_patterns(&mut self, has_guard: bool, pat: &Pat<'_>) {
if !self.tcx.features().move_ref_pattern {
check_legality_of_move_bindings(self, has_guard, pat);
}
fn check_patterns(&mut self, pat: &Pat<'_>) {
pat.walk_always(|pat| check_borrow_conflicts_in_at_patterns(self, pat));
if !self.tcx.features().bindings_after_at {
check_legality_of_bindings_in_at_patterns(self, pat);
Expand Down Expand Up @@ -165,7 +162,7 @@ impl<'tcx> MatchVisitor<'_, 'tcx> {
) {
for arm in arms {
// Check the arm for some things unrelated to exhaustiveness.
self.check_patterns(arm.guard.is_some(), &arm.pat);
self.check_patterns(&arm.pat);
}

let mut cx = self.new_cx(scrut.hir_id);
Expand Down Expand Up @@ -601,65 +598,6 @@ fn is_binding_by_move(cx: &MatchVisitor<'_, '_>, hir_id: HirId, span: Span) -> b
!cx.typeck_results.node_type(hir_id).is_copy_modulo_regions(cx.tcx.at(span), cx.param_env)
}

/// Check the legality of legality of by-move bindings.
fn check_legality_of_move_bindings(cx: &mut MatchVisitor<'_, '_>, has_guard: bool, pat: &Pat<'_>) {
let sess = cx.tcx.sess;
let typeck_results = cx.typeck_results;

// Find all by-ref spans.
let mut by_ref_spans = Vec::new();
pat.each_binding(|_, hir_id, span, _| {
if let Some(ty::BindByReference(_)) =
typeck_results.extract_binding_mode(sess, hir_id, span)
{
by_ref_spans.push(span);
}
});

// Find bad by-move spans:
let by_move_spans = &mut Vec::new();
let mut check_move = |p: &Pat<'_>, sub: Option<&Pat<'_>>| {
// Check legality of moving out of the enum.
//
// `x @ Foo(..)` is legal, but `x @ Foo(y)` isn't.
if sub.map_or(false, |p| p.contains_bindings()) {
struct_span_err!(sess, p.span, E0007, "cannot bind by-move with sub-bindings")
.span_label(p.span, "binds an already bound by-move value by moving it")
.emit();
} else if !has_guard && !by_ref_spans.is_empty() {
by_move_spans.push(p.span);
}
};
pat.walk_always(|p| {
if let hir::PatKind::Binding(.., sub) = &p.kind {
if let Some(ty::BindByValue(_)) =
typeck_results.extract_binding_mode(sess, p.hir_id, p.span)
{
if is_binding_by_move(cx, p.hir_id, p.span) {
check_move(p, sub.as_deref());
}
}
}
});

// Found some bad by-move spans, error!
if !by_move_spans.is_empty() {
let mut err = feature_err(
&sess.parse_sess,
sym::move_ref_pattern,
by_move_spans.clone(),
"binding by-move and by-ref in the same pattern is unstable",
);
for span in by_ref_spans.iter() {
err.span_label(*span, "by-ref pattern here");
}
for span in by_move_spans.iter() {
err.span_label(*span, "by-move pattern here");
}
err.emit();
}
}

/// Check that there are no borrow or move conflicts in `binding @ subpat` patterns.
///
/// For example, this would reject:
Expand Down
2 changes: 0 additions & 2 deletions src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs
View file
Expand Up @@ -3,8 +3,6 @@
#![feature(or_patterns)]
#![feature(box_patterns)]

#![feature(move_ref_pattern)]

enum Test {
Foo,
Bar,
Expand Down
34 changes: 17 additions & 17 deletions src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
View file
@@ -1,5 +1,5 @@
error: cannot borrow value as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:40:9
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:38:9
|
LL | ref foo @ [.., ref mut bar] => (),
| -------^^^^^^^^-----------^
Expand All @@ -8,7 +8,7 @@ LL | ref foo @ [.., ref mut bar] => (),
| immutable borrow, by `foo`, occurs here

error: cannot borrow value as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:124:9
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:122:9
|
LL | ref foo @ Some(box ref mut s) => (),
| -------^^^^^^^^^^^^---------^
Expand All @@ -17,7 +17,7 @@ LL | ref foo @ Some(box ref mut s) => (),
| immutable borrow, by `foo`, occurs here

error[E0382]: borrow of moved value: `x`
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:22:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:20:5
|
LL | fn bindings_after_at_slice_patterns_move_binding(x: [String; 4]) {
| - move occurs because `x` has type `[String; 4]`, which does not implement the `Copy` trait
Expand All @@ -29,7 +29,7 @@ LL | &x;
| ^^ value borrowed here after move

error[E0502]: cannot borrow `x` as immutable because it is also borrowed as mutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:32:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:30:5
|
LL | ref mut foo @ [.., _] => Some(foo),
| --------------------- mutable borrow occurs here
Expand All @@ -41,7 +41,7 @@ LL | drop(r);
| - mutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:54:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:52:5
|
LL | [ref foo @ .., ref bar] => Some(foo),
| ------------ immutable borrow occurs here
Expand All @@ -53,7 +53,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:66:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:64:5
|
LL | ref foo @ [.., ref bar] => Some(foo),
| ----------------------- immutable borrow occurs here
Expand All @@ -65,7 +65,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0382]: borrow of moved value: `x`
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:80:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:78:5
|
LL | fn bindings_after_at_or_patterns_move(x: Option<Test>) {
| - move occurs because `x` has type `Option<Test>`, which does not implement the `Copy` trait
Expand All @@ -80,7 +80,7 @@ LL | &x;
| ^^ value borrowed here after move

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:90:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:88:5
|
LL | ref foo @ Some(Test::Foo | Test::Bar) => Some(foo),
| ------------------------------------- immutable borrow occurs here
Expand All @@ -92,7 +92,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0502]: cannot borrow `x` as immutable because it is also borrowed as mutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:102:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:100:5
|
LL | ref mut foo @ Some(Test::Foo | Test::Bar) => Some(foo),
| ----------------------------------------- mutable borrow occurs here
Expand All @@ -104,7 +104,7 @@ LL | drop(r);
| - mutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:116:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:114:5
|
LL | ref foo @ Some(box ref s) => Some(foo),
| ------------------------- immutable borrow occurs here
Expand All @@ -116,7 +116,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0382]: borrow of moved value: `x`
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:138:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:136:5
|
LL | fn bindings_after_at_slice_patterns_or_patterns_moves(x: [Option<Test>; 4]) {
| - move occurs because `x` has type `[Option<Test>; 4]`, which does not implement the `Copy` trait
Expand All @@ -131,7 +131,7 @@ LL | &x;
| ^^ value borrowed here after move

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:148:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:146:5
|
LL | ref a @ [ref b @ .., Some(Test::Foo | Test::Bar)] => Some(a),
| ------------------------------------------------- immutable borrow occurs here
Expand All @@ -143,7 +143,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:160:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:158:5
|
LL | ref a @ [ref b @ .., Some(Test::Foo | Test::Bar)] => Some(b),
| ---------- immutable borrow occurs here
Expand All @@ -155,7 +155,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:174:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:172:5
|
LL | [_, ref a @ Some(box ref b), ..] => Some(a),
| ----------------------- immutable borrow occurs here
Expand All @@ -167,7 +167,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:190:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:188:5
|
LL | [_, ref a @ Some(box Test::Foo | box Test::Bar), ..] => Some(a),
| ------------------------------------------- immutable borrow occurs here
Expand All @@ -179,7 +179,7 @@ LL | drop(r);
| - immutable borrow later used here

error[E0502]: cannot borrow `x` as immutable because it is also borrowed as mutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:204:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:202:5
|
LL | [_, ref mut a @ Some(box Test::Foo | box Test::Bar), ..] => Some(a),
| ----------------------------------------------- mutable borrow occurs here
Expand All @@ -191,7 +191,7 @@ LL | drop(r);
| - mutable borrow later used here

error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:218:5
--> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:216:5
|
LL | ref a @ [_, ref b @ Some(box Test::Foo | box Test::Bar), ..] => Some(a),
| ------------------------------------------------------------ immutable borrow occurs here
Expand Down
2 changes: 0 additions & 2 deletions src/test/ui/drop/dynamic-drop-async.rs
View file
Expand Up @@ -7,8 +7,6 @@
// edition:2018
// ignore-wasm32-bare compiled with panic=abort by default

#![feature(move_ref_pattern)]

#![allow(unused)]

use std::{
Expand Down
1 change: 0 additions & 1 deletion src/test/ui/drop/dynamic-drop.rs
View file
Expand Up @@ -2,7 +2,6 @@
// ignore-wasm32-bare compiled with panic=abort by default

#![feature(generators, generator_trait, untagged_unions)]
#![feature(move_ref_pattern)]
#![feature(bindings_after_at)]

#![allow(unused_assignments)]
Expand Down
11 changes: 0 additions & 11 deletions src/test/ui/error-codes/E0007.rs
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This file was deleted.

22 changes: 0 additions & 22 deletions src/test/ui/error-codes/E0007.stderr
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This file was deleted.

1 change: 0 additions & 1 deletion .../ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.rs
View file
Expand Up @@ -3,7 +3,6 @@
// where one side is by-ref and the other is by-move.

#![feature(bindings_after_at)]
#![feature(move_ref_pattern)]

struct X {
x: (),
Expand Down
12 changes: 6 additions & 6 deletions ...pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
View file
@@ -1,5 +1,5 @@
error: cannot move out of value because it is borrowed
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:15:14
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:14:14
|
LL | Some(ref _y @ _z) => {}
| ------^^^--
Expand All @@ -8,7 +8,7 @@ LL | Some(ref _y @ _z) => {}
| value borrowed, by `_y`, here

error: borrow of moved value
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:21:14
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:20:14
|
LL | Some(_z @ ref _y) => {}
| --^^^------
Expand All @@ -18,7 +18,7 @@ LL | Some(_z @ ref _y) => {}
| move occurs because `_z` has type `X` which does not implement the `Copy` trait

error: cannot move out of value because it is borrowed
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:29:14
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:28:14
|
LL | Some(ref mut _y @ _z) => {}
| ----------^^^--
Expand All @@ -27,7 +27,7 @@ LL | Some(ref mut _y @ _z) => {}
| value borrowed, by `_y`, here

error: borrow of moved value
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:35:14
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:34:14
|
LL | Some(_z @ ref mut _y) => {}
| --^^^----------
Expand All @@ -37,7 +37,7 @@ LL | Some(_z @ ref mut _y) => {}
| move occurs because `_z` has type `X` which does not implement the `Copy` trait

error[E0382]: borrow of moved value
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:21:19
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:20:19
|
LL | Some(_z @ ref _y) => {}
| -----^^^^^^
Expand All @@ -52,7 +52,7 @@ LL | Some(ref _z @ ref _y) => {}
| ^^^

error[E0382]: borrow of moved value
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:35:19
--> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:34:19
|
LL | Some(_z @ ref mut _y) => {}
| -----^^^^^^^^^^
Expand Down

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