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oli-obkoli-obk
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Close accidental promotion check hole
1 parent bb67558 commit 9ec72df

7 files changed

+99
-16
lines changed

‎compiler/rustc_const_eval/src/transform/promote_consts.rs

+6-8
Original file line numberDiff line numberDiff line change
@@ -216,12 +216,6 @@ impl<'tcx> Validator<'_, 'tcx> {
216216
return Err(Unpromotable);
217217
}
218218

219-
// We cannot promote things that need dropping, since the promoted value
220-
// would not get dropped.
221-
if self.qualif_local::<qualifs::NeedsDrop>(place.local) {
222-
return Err(Unpromotable);
223-
}
224-
225219
Ok(())
226220
}
227221
_ => bug!(),
@@ -262,13 +256,17 @@ impl<'tcx> Validator<'_, 'tcx> {
262256
}
263257
}
264258
} else {
265-
let span = self.body.local_decls[local].source_info.span;
266-
span_bug!(span, "{:?} not promotable, qualif_local shouldn't have been called", local);
259+
false
267260
}
268261
}
269262

270263
fn validate_local(&mut self, local: Local) -> Result<(), Unpromotable> {
271264
if let TempState::Defined { location: loc, uses, valid } = self.temps[local] {
265+
// We cannot promote things that need dropping, since the promoted value
266+
// would not get dropped.
267+
if self.qualif_local::<qualifs::NeedsDrop>(local) {
268+
return Err(Unpromotable);
269+
}
272270
valid.or_else(|_| {
273271
let ok = {
274272
let block = &self.body[loc.block];

‎src/test/ui/consts/promoted_const_call.rs

+2-3
Original file line numberDiff line numberDiff line change
@@ -1,13 +1,12 @@
1-
// check-pass
2-
// known-bug: #91009
3-
41
#![feature(const_mut_refs)]
52
#![feature(const_trait_impl)]
63
struct Panic;
74
impl const Drop for Panic { fn drop(&mut self) { panic!(); } }
85
pub const fn id<T>(x: T) -> T { x }
96
pub const C: () = {
107
let _: &'static _ = &id(&Panic);
8+
//~^ ERROR: temporary value dropped while borrowed
9+
//~| ERROR: temporary value dropped while borrowed
1110
};
1211

1312
fn main() {}

‎src/test/ui/consts/promoted_const_call.stderr

+23
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
1+
error[E0716]: temporary value dropped while borrowed
2+
--> $DIR/promoted_const_call.rs:7:26
3+
|
4+
LL | let _: &'static _ = &id(&Panic);
5+
| ---------- ^^^^^^^^^^ creates a temporary value which is freed while still in use
6+
| |
7+
| type annotation requires that borrow lasts for `'static`
8+
...
9+
LL | };
10+
| - temporary value is freed at the end of this statement
11+
12+
error[E0716]: temporary value dropped while borrowed
13+
--> $DIR/promoted_const_call.rs:7:30
14+
|
15+
LL | let _: &'static _ = &id(&Panic);
16+
| ---------- ^^^^^ - temporary value is freed at the end of this statement
17+
| | |
18+
| | creates a temporary value which is freed while still in use
19+
| type annotation requires that borrow lasts for `'static`
20+
21+
error: aborting due to 2 previous errors
22+
23+
For more information about this error, try `rustc --explain E0716`.

‎src/test/ui/consts/promoted_const_call2.rs

+3-3
Original file line numberDiff line numberDiff line change
@@ -1,10 +1,10 @@
1-
// check-pass
2-
// known-bug: #91009
3-
41
#![feature(const_precise_live_drops)]
52
pub const fn id<T>(x: T) -> T { x }
63
pub const C: () = {
74
let _: &'static _ = &id(&String::new());
5+
//~^ ERROR: temporary value dropped while borrowed
6+
//~| ERROR: temporary value dropped while borrowed
7+
//~| ERROR: destructor of `String` cannot be evaluated at compile-time
88
};
99

1010
fn main() {}

‎src/test/ui/consts/promoted_const_call2.stderr

+30
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,30 @@
1+
error[E0716]: temporary value dropped while borrowed
2+
--> $DIR/promoted_const_call2.rs:4:26
3+
|
4+
LL | let _: &'static _ = &id(&String::new());
5+
| ---------- ^^^^^^^^^^^^^^^^^^ creates a temporary value which is freed while still in use
6+
| |
7+
| type annotation requires that borrow lasts for `'static`
8+
...
9+
LL | };
10+
| - temporary value is freed at the end of this statement
11+
12+
error[E0716]: temporary value dropped while borrowed
13+
--> $DIR/promoted_const_call2.rs:4:30
14+
|
15+
LL | let _: &'static _ = &id(&String::new());
16+
| ---------- ^^^^^^^^^^^^^ - temporary value is freed at the end of this statement
17+
| | |
18+
| | creates a temporary value which is freed while still in use
19+
| type annotation requires that borrow lasts for `'static`
20+
21+
error[E0493]: destructor of `String` cannot be evaluated at compile-time
22+
--> $DIR/promoted_const_call2.rs:4:30
23+
|
24+
LL | let _: &'static _ = &id(&String::new());
25+
| ^^^^^^^^^^^^^ the destructor for this type cannot be evaluated in constants
26+
27+
error: aborting due to 3 previous errors
28+
29+
Some errors have detailed explanations: E0493, E0716.
30+
For more information about an error, try `rustc --explain E0493`.

‎src/test/ui/consts/promoted_const_call3.rs

+3-1
Original file line numberDiff line numberDiff line change
@@ -6,9 +6,11 @@ pub const C: () = {
66

77
let _: &'static _ = &id(&String::new());
88
//~^ ERROR: destructor of `String` cannot be evaluated at compile-time
9+
//~| ERROR: temporary value dropped while borrowed
10+
//~| ERROR: temporary value dropped while borrowed
911

1012
let _: &'static _ = &std::mem::ManuallyDrop::new(String::new());
11-
// Promoted. bug!
13+
//~^ ERROR: temporary value dropped while borrowed
1214
};
1315

1416
fn main() {}

‎src/test/ui/consts/promoted_const_call3.stderr

+32-1
Original file line numberDiff line numberDiff line change
@@ -26,7 +26,38 @@ LL | let _: &'static _ = &String::new();
2626
LL | };
2727
| - temporary value is freed at the end of this statement
2828

29-
error: aborting due to 3 previous errors
29+
error[E0716]: temporary value dropped while borrowed
30+
--> $DIR/promoted_const_call3.rs:7:26
31+
|
32+
LL | let _: &'static _ = &id(&String::new());
33+
| ---------- ^^^^^^^^^^^^^^^^^^ creates a temporary value which is freed while still in use
34+
| |
35+
| type annotation requires that borrow lasts for `'static`
36+
...
37+
LL | };
38+
| - temporary value is freed at the end of this statement
39+
40+
error[E0716]: temporary value dropped while borrowed
41+
--> $DIR/promoted_const_call3.rs:7:30
42+
|
43+
LL | let _: &'static _ = &id(&String::new());
44+
| ---------- ^^^^^^^^^^^^^ - temporary value is freed at the end of this statement
45+
| | |
46+
| | creates a temporary value which is freed while still in use
47+
| type annotation requires that borrow lasts for `'static`
48+
49+
error[E0716]: temporary value dropped while borrowed
50+
--> $DIR/promoted_const_call3.rs:12:26
51+
|
52+
LL | let _: &'static _ = &std::mem::ManuallyDrop::new(String::new());
53+
| ---------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ creates a temporary value which is freed while still in use
54+
| |
55+
| type annotation requires that borrow lasts for `'static`
56+
LL |
57+
LL | };
58+
| - temporary value is freed at the end of this statement
59+
60+
error: aborting due to 6 previous errors
3061

3162
Some errors have detailed explanations: E0493, E0716.
3263
For more information about an error, try `rustc --explain E0493`.

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