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RalfJungRalfJung
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const checks: avoid 'top-level scope' terminology
1 parent e61dd43 commit 2de51b4

28 files changed

+56
-60
lines changed

‎compiler/rustc_const_eval/messages.ftl

Lines changed: 8 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -125,15 +125,13 @@ const_eval_incompatible_types =
125125
calling a function with argument of type {$callee_ty} passing data of type {$caller_ty}
126126
127127
const_eval_interior_mutable_borrow_escaping =
128-
interior mutable shared borrows of lifetime-extended temporaries in the top-level scope of a {const_eval_const_context} are not allowed
128+
interior mutable shared borrows of temporaries that have their lifetime extended until the end of the program are not allowed
129129
.label = this borrow of an interior mutable value refers to a lifetime-extended temporary
130130
.help = to fix this, the value can be extracted to a separate `static` item and then referenced
131131
.teach_note =
132-
This creates a raw pointer to a temporary that has its lifetime extended to last for the entire program.
133-
Lifetime-extended temporaries in constants and statics must be immutable.
134-
This is to avoid accidentally creating shared mutable state.
135-
136-
132+
Temporaries in constants and statics can have their lifetime extended until the end of the program.
133+
(See <https://doc.rust-lang.org/reference/destructors.html#r-destructors.scope.lifetime-extension.static>.)
134+
To avoid accidentally creating global mutable state, such temporaries must be immutable.
137135
If you really want global mutable state, try using an interior mutable `static` or a `static mut`.
138136
139137
const_eval_intern_kind = {$kind ->
@@ -215,13 +213,11 @@ const_eval_modified_global =
215213
modifying a static's initial value from another static's initializer
216214
217215
const_eval_mutable_borrow_escaping =
218-
mutable borrows of lifetime-extended temporaries in the top-level scope of a {const_eval_const_context} are not allowed
216+
mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
219217
.teach_note =
220-
This creates a reference to a temporary that has its lifetime extended to last for the entire program.
221-
Lifetime-extended temporaries in constants and statics must be immutable.
222-
This is to avoid accidentally creating shared mutable state.
223-
224-
218+
Temporaries in constants and statics can have their lifetime extended until the end of the program.
219+
(See <https://doc.rust-lang.org/reference/destructors.html#r-destructors.scope.lifetime-extension.static>.)
220+
To avoid accidentally creating global mutable state, such temporaries must be immutable.
225221
If you really want global mutable state, try using an interior mutable `static` or a `static mut`.
226222
227223
const_eval_mutable_ptr_in_final = encountered mutable pointer in final value of {const_eval_intern_kind}

‎tests/ui/consts/const-mut-refs/issue-76510.rs

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,7 @@
11
use std::mem::{transmute, ManuallyDrop};
22

33
const S: &'static mut str = &mut " hello ";
4-
//~^ ERROR: mutable borrows of lifetime-extended temporaries
4+
//~^ ERROR: mutable borrows of temporaries
55

66
const fn trigger() -> [(); unsafe {
77
let s = transmute::<(*const u8, usize), &ManuallyDrop<str>>((S.as_ptr(), 3));

‎tests/ui/consts/const-mut-refs/issue-76510.stderr

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a constant are not allowed
1+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
22
--> $DIR/issue-76510.rs:3:29
33
|
44
LL | const S: &'static mut str = &mut " hello ";

‎tests/ui/consts/const-mut-refs/mut_ref_in_final.rs

Lines changed: 6 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -12,13 +12,13 @@ const A: *const i32 = &4;
1212
// It could be made sound to allow it to compile,
1313
// but we do not want to allow this to compile,
1414
// as that would be an enormous footgun in oli-obk's opinion.
15-
const B: *mut i32 = &mut 4; //~ ERROR mutable borrows of lifetime-extended temporaries
15+
const B: *mut i32 = &mut 4; //~ ERROR mutable borrows of temporaries
1616

1717
// Ok, no actual mutable allocation exists
1818
const B2: Option<&mut i32> = None;
1919

2020
// Not ok, can't prove that no mutable allocation ends up in final value
21-
const B3: Option<&mut i32> = Some(&mut 42); //~ ERROR mutable borrows of lifetime-extended temporaries
21+
const B3: Option<&mut i32> = Some(&mut 42); //~ ERROR mutable borrows of temporaries
2222

2323
const fn helper(x: &mut i32) -> Option<&mut i32> { Some(x) }
2424
const B4: Option<&mut i32> = helper(&mut 42); //~ ERROR temporary value dropped while borrowed
@@ -69,13 +69,13 @@ unsafe impl<T> Sync for SyncPtr<T> {}
6969
// (This relies on `SyncPtr` being a curly brace struct.)
7070
// However, we intern the inner memory as read-only, so this must be rejected.
7171
static RAW_MUT_CAST_S: SyncPtr<i32> = SyncPtr { x : &mut 42 as *mut _ as *const _ };
72-
//~^ ERROR mutable borrows of lifetime-extended temporaries
72+
//~^ ERROR mutable borrows of temporaries
7373
static RAW_MUT_COERCE_S: SyncPtr<i32> = SyncPtr { x: &mut 0 };
74-
//~^ ERROR mutable borrows of lifetime-extended temporaries
74+
//~^ ERROR mutable borrows of temporaries
7575
const RAW_MUT_CAST_C: SyncPtr<i32> = SyncPtr { x : &mut 42 as *mut _ as *const _ };
76-
//~^ ERROR mutable borrows of lifetime-extended temporaries
76+
//~^ ERROR mutable borrows of temporaries
7777
const RAW_MUT_COERCE_C: SyncPtr<i32> = SyncPtr { x: &mut 0 };
78-
//~^ ERROR mutable borrows of lifetime-extended temporaries
78+
//~^ ERROR mutable borrows of temporaries
7979

8080
fn main() {
8181
println!("{}", unsafe { *A });

‎tests/ui/consts/const-mut-refs/mut_ref_in_final.stderr

Lines changed: 6 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -1,10 +1,10 @@
1-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a constant are not allowed
1+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
22
--> $DIR/mut_ref_in_final.rs:15:21
33
|
44
LL | const B: *mut i32 = &mut 4;
55
| ^^^^^^
66

7-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a constant are not allowed
7+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
88
--> $DIR/mut_ref_in_final.rs:21:35
99
|
1010
LL | const B3: Option<&mut i32> = Some(&mut 42);
@@ -72,25 +72,25 @@ LL | static mut FOO3: NotAMutex<&mut i32> = NotAMutex(UnsafeCell::new(&mut 42));
7272
| | creates a temporary value which is freed while still in use
7373
| using this value as a static requires that borrow lasts for `'static`
7474

75-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a static are not allowed
75+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
7676
--> $DIR/mut_ref_in_final.rs:71:53
7777
|
7878
LL | static RAW_MUT_CAST_S: SyncPtr<i32> = SyncPtr { x : &mut 42 as *mut _ as *const _ };
7979
| ^^^^^^^
8080

81-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a static are not allowed
81+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
8282
--> $DIR/mut_ref_in_final.rs:73:54
8383
|
8484
LL | static RAW_MUT_COERCE_S: SyncPtr<i32> = SyncPtr { x: &mut 0 };
8585
| ^^^^^^
8686

87-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a constant are not allowed
87+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
8888
--> $DIR/mut_ref_in_final.rs:75:52
8989
|
9090
LL | const RAW_MUT_CAST_C: SyncPtr<i32> = SyncPtr { x : &mut 42 as *mut _ as *const _ };
9191
| ^^^^^^^
9292

93-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a constant are not allowed
93+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
9494
--> $DIR/mut_ref_in_final.rs:77:53
9595
|
9696
LL | const RAW_MUT_COERCE_C: SyncPtr<i32> = SyncPtr { x: &mut 0 };

‎tests/ui/consts/const-promoted-opaque.atomic.stderr

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@ LL |
77
LL | };
88
| - value is dropped here
99

10-
error[E0492]: interior mutable shared borrows of lifetime-extended temporaries in the top-level scope of a constant are not allowed
10+
error[E0492]: interior mutable shared borrows of temporaries that have their lifetime extended until the end of the program are not allowed
1111
--> $DIR/const-promoted-opaque.rs:36:19
1212
|
1313
LL | const BAZ: &Foo = &FOO;

‎tests/ui/consts/const-promoted-opaque.rs

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -34,7 +34,7 @@ const BAR: () = {
3434
};
3535

3636
const BAZ: &Foo = &FOO;
37-
//[atomic]~^ ERROR: interior mutable shared borrows of lifetime-extended temporaries
37+
//[atomic]~^ ERROR: interior mutable shared borrows of temporaries
3838

3939
fn main() {
4040
let _: &'static _ = &FOO;

‎tests/ui/consts/issue-17718-const-bad-values.rs

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,7 @@
55
#![allow(static_mut_refs)]
66

77
const C1: &'static mut [usize] = &mut [];
8-
//~^ ERROR: mutable borrows of lifetime-extended temporaries
8+
//~^ ERROR: mutable borrows of temporaries
99

1010
static mut S: i32 = 3;
1111
const C2: &'static mut i32 = unsafe { &mut S };

‎tests/ui/consts/issue-17718-const-bad-values.stderr

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
error[E0764]: mutable borrows of lifetime-extended temporaries in the top-level scope of a constant are not allowed
1+
error[E0764]: mutable borrows of temporaries that have their lifetime extended until the end of the program are not allowed
22
--> $DIR/issue-17718-const-bad-values.rs:7:34
33
|
44
LL | const C1: &'static mut [usize] = &mut [];

‎tests/ui/consts/issue-17718-const-borrow.rs

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -2,13 +2,13 @@ use std::cell::UnsafeCell;
22

33
const A: UnsafeCell<usize> = UnsafeCell::new(1);
44
const B: &'static UnsafeCell<usize> = &A;
5-
//~^ ERROR: interior mutable shared borrows of lifetime-extended temporaries
5+
//~^ ERROR: interior mutable shared borrows of temporaries
66

77
struct C { a: UnsafeCell<usize> }
88
const D: C = C { a: UnsafeCell::new(1) };
99
const E: &'static UnsafeCell<usize> = &D.a;
10-
//~^ ERROR: interior mutable shared borrows of lifetime-extended temporaries
10+
//~^ ERROR: interior mutable shared borrows of temporaries
1111
const F: &'static C = &D;
12-
//~^ ERROR: interior mutable shared borrows of lifetime-extended temporaries
12+
//~^ ERROR: interior mutable shared borrows of temporaries
1313

1414
fn main() {}

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