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Deny calls to non-#[const_trait] methods in MIR constck
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-324
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75 files changed

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‎compiler/rustc_const_eval/src/check_consts/check.rs

Lines changed: 19 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -616,14 +616,16 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
616616

617617
let mut is_trait = false;
618618
// Attempting to call a trait method?
619-
if tcx.trait_of_item(callee).is_some() {
619+
if let Some(trait_did) = tcx.trait_of_item(callee) {
620620
trace!("attempting to call a trait method");
621+
622+
let trait_is_const = tcx.is_const_trait(trait_did);
621623
// trait method calls are only permitted when `effects` is enabled.
622-
// we don't error, since that is handled by typeck. We try to resolve
623-
// the trait into the concrete method, and uses that for const stability
624-
// checks.
624+
// typeck ensures the conditions for calling a const trait method are met,
625+
// so we only error if the trait isn't const. We try to resolve the trait
626+
// into the concrete method, and uses that for const stability checks.
625627
// FIXME(effects) we might consider moving const stability checks to typeck as well.
626-
if tcx.features().effects() {
628+
if tcx.features().effects() && trait_is_const {
627629
// This skips the check below that ensures we only call `const fn`.
628630
is_trait = true;
629631

@@ -638,17 +640,24 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
638640
callee = def;
639641
}
640642
} else {
643+
// if the trait is const but the user has not enabled the feature(s),
644+
// suggest them.
645+
let feature = if trait_is_const {
646+
Some(if tcx.features().const_trait_impl() {
647+
sym::effects
648+
} else {
649+
sym::const_trait_impl
650+
})
651+
} else {
652+
None
653+
};
641654
self.check_op(ops::FnCallNonConst {
642655
caller,
643656
callee,
644657
args: fn_args,
645658
span: *fn_span,
646659
call_source,
647-
feature: Some(if tcx.features().const_trait_impl() {
648-
sym::effects
649-
} else {
650-
sym::const_trait_impl
651-
}),
660+
feature,
652661
});
653662
// If we allowed this, we're in miri-unleashed mode, so we might
654663
// as well skip the remaining checks.

‎tests/ui/const-generics/generic_const_exprs/unify-op-with-fn-call.stderr

Lines changed: 21 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -27,11 +27,13 @@ LL + #[derive(ConstParamTy)]
2727
LL | struct Foo(u8);
2828
|
2929

30-
error[E0284]: type annotations needed: cannot normalize `foo<N>::{constant#0}`
31-
--> $DIR/unify-op-with-fn-call.rs:20:25
30+
error[E0015]: cannot call non-const operator in constants
31+
--> $DIR/unify-op-with-fn-call.rs:20:39
3232
|
3333
LL | fn foo<const N: Foo>(a: Evaluatable<{ N + N }>) {
34-
| ^^^^^^^^^^^^^^^^^^^^^^ cannot normalize `foo<N>::{constant#0}`
34+
| ^^^^^
35+
|
36+
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
3537

3638
error[E0741]: `Foo` must implement `ConstParamTy` to be used as the type of a const generic parameter
3739
--> $DIR/unify-op-with-fn-call.rs:20:17
@@ -63,19 +65,29 @@ error[E0284]: type annotations needed: cannot normalize `foo2<N>::{constant#0}`
6365
LL | fn foo2<const N: usize>(a: Evaluatable2<{ N + N }>) {
6466
| ^^^^^^^^^^^^^^^^^^^^^^^ cannot normalize `foo2<N>::{constant#0}`
6567

66-
error[E0284]: type annotations needed: cannot normalize `foo<N>::{constant#0}`
67-
--> $DIR/unify-op-with-fn-call.rs:21:11
68+
error[E0015]: cannot call non-const fn `<Foo as Add>::add` in constants
69+
--> $DIR/unify-op-with-fn-call.rs:21:13
6870
|
6971
LL | bar::<{ std::ops::Add::add(N, N) }>();
70-
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot normalize `foo<N>::{constant#0}`
72+
| ^^^^^^^^^^^^^^^^^^^^^^^^
73+
|
74+
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
75+
76+
error[E0015]: cannot call non-const fn `<usize as Add>::add` in constants
77+
--> $DIR/unify-op-with-fn-call.rs:30:14
78+
|
79+
LL | bar2::<{ std::ops::Add::add(N, N) }>();
80+
| ^^^^^^^^^^^^^^^^^^^^^^^^
81+
|
82+
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
7183

7284
error[E0284]: type annotations needed: cannot normalize `foo2<N>::{constant#0}`
7385
--> $DIR/unify-op-with-fn-call.rs:30:12
7486
|
7587
LL | bar2::<{ std::ops::Add::add(N, N) }>();
7688
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot normalize `foo2<N>::{constant#0}`
7789

78-
error: aborting due to 9 previous errors
90+
error: aborting due to 10 previous errors
7991

80-
Some errors have detailed explanations: E0284, E0741.
81-
For more information about an error, try `rustc --explain E0284`.
92+
Some errors have detailed explanations: E0015, E0284, E0741.
93+
For more information about an error, try `rustc --explain E0015`.

‎tests/ui/const-generics/issue-93647.stderr

Lines changed: 0 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -6,10 +6,6 @@ LL | (||1usize)()
66
|
77
= note: closures need an RFC before allowed to be called in constants
88
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
9-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
10-
|
11-
LL + #![feature(const_trait_impl)]
12-
|
139

1410
error: aborting due to 1 previous error
1511

‎tests/ui/const-generics/issues/issue-90318.stderr

Lines changed: 0 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -29,10 +29,6 @@ LL | If<{ TypeId::of::<T>() != TypeId::of::<()>() }>: True,
2929
note: impl defined here, but it is not `const`
3030
--> $SRC_DIR/core/src/any.rs:LL:COL
3131
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
32-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
33-
|
34-
LL + #![feature(const_trait_impl)]
35-
|
3632

3733
error[E0015]: cannot call non-const operator in constants
3834
--> $DIR/issue-90318.rs:22:10
@@ -43,10 +39,6 @@ LL | If<{ TypeId::of::<T>() != TypeId::of::<()>() }>: True,
4339
note: impl defined here, but it is not `const`
4440
--> $SRC_DIR/core/src/any.rs:LL:COL
4541
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
46-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
47-
|
48-
LL + #![feature(const_trait_impl)]
49-
|
5042

5143
error: aborting due to 4 previous errors
5244

‎tests/ui/consts/closure-in-foreign-crate.rs

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -1,8 +1,8 @@
1-
//@ aux-build:closure-in-foreign-crate.rs
1+
// FIXME(effects) aux-build:closure-in-foreign-crate.rs
22
//@ build-pass
33

4-
extern crate closure_in_foreign_crate;
4+
// FIXME(effects) extern crate closure_in_foreign_crate;
55

6-
const _: () = closure_in_foreign_crate::test();
6+
// FIXME(effects) const _: () = closure_in_foreign_crate::test();
77

88
fn main() {}

‎tests/ui/consts/const-fn-error.stderr

Lines changed: 0 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -22,10 +22,6 @@ LL | for i in 0..x {
2222
note: impl defined here, but it is not `const`
2323
--> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
2424
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
25-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
26-
|
27-
LL + #![feature(const_trait_impl)]
28-
|
2925

3026
error[E0015]: cannot call non-const fn `<std::ops::Range<usize> as Iterator>::next` in constant functions
3127
--> $DIR/const-fn-error.rs:5:14
@@ -34,10 +30,6 @@ LL | for i in 0..x {
3430
| ^^^^
3531
|
3632
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
37-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
38-
|
39-
LL + #![feature(const_trait_impl)]
40-
|
4133

4234
error: aborting due to 3 previous errors
4335

‎tests/ui/consts/const-for-feature-gate.stderr

Lines changed: 0 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -17,10 +17,6 @@ LL | for _ in 0..5 {}
1717
note: impl defined here, but it is not `const`
1818
--> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
1919
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
20-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
21-
|
22-
LL + #![feature(const_trait_impl)]
23-
|
2420

2521
error[E0015]: cannot call non-const fn `<std::ops::Range<i32> as Iterator>::next` in constants
2622
--> $DIR/const-for-feature-gate.rs:4:14
@@ -29,10 +25,6 @@ LL | for _ in 0..5 {}
2925
| ^^^^
3026
|
3127
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
32-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
33-
|
34-
LL + #![feature(const_trait_impl)]
35-
|
3628

3729
error: aborting due to 3 previous errors
3830

‎tests/ui/consts/const-for.stderr

Lines changed: 0 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -7,10 +7,6 @@ LL | for _ in 0..5 {}
77
note: impl defined here, but it is not `const`
88
--> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
99
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
10-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
11-
|
12-
LL + #![feature(const_trait_impl)]
13-
|
1410

1511
error[E0015]: cannot call non-const fn `<std::ops::Range<i32> as Iterator>::next` in constants
1612
--> $DIR/const-for.rs:4:14
@@ -19,10 +15,6 @@ LL | for _ in 0..5 {}
1915
| ^^^^
2016
|
2117
= note: calls in constants are limited to constant functions, tuple structs and tuple variants
22-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
23-
|
24-
LL + #![feature(const_trait_impl)]
25-
|
2618

2719
error: aborting due to 2 previous errors
2820

‎tests/ui/consts/const-try-feature-gate.stderr

Lines changed: 0 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -17,10 +17,6 @@ LL | Some(())?;
1717
note: impl defined here, but it is not `const`
1818
--> $SRC_DIR/core/src/option.rs:LL:COL
1919
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
20-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
21-
|
22-
LL + #![feature(const_trait_impl)]
23-
|
2420

2521
error[E0015]: `?` cannot convert from residual of `Option<()>` in constant functions
2622
--> $DIR/const-try-feature-gate.rs:4:5
@@ -31,10 +27,6 @@ LL | Some(())?;
3127
note: impl defined here, but it is not `const`
3228
--> $SRC_DIR/core/src/option.rs:LL:COL
3329
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
34-
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
35-
|
36-
LL + #![feature(const_trait_impl)]
37-
|
3830

3931
error: aborting due to 3 previous errors
4032

‎tests/ui/consts/const-try.rs

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -34,6 +34,8 @@ impl const Try for TryMe {
3434

3535
const fn t() -> TryMe {
3636
TryMe?;
37+
//~^ ERROR `?` cannot determine the branch of `TryMe` in constant functions
38+
//~| ERROR `?` cannot convert from residual of `TryMe` in constant functions
3739
TryMe
3840
}
3941

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