From 82ab171673d10f16c67a52d50ef1f5b197656bbd Mon Sep 17 00:00:00 2001
From: Katherine Philip <kurerunoshikaku@yahoo.com>
Date: Wed, 13 Jul 2022 09:42:25 -0700
Subject: [PATCH 1/4] Use emit_inference_failure_err for ConstEvaluatable
predicates
---
.../src/traits/error_reporting/mod.rs | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index aa1c9136289..8396df4a243 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -2156,6 +2156,22 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
}
}
+ ty::PredicateKind::ConstEvaluatable(data) => {
+ let subst = data.substs.iter().find(|g| g.has_infer_types_or_consts());
+ if let Some(subst) = subst {
+ let mut err = self.emit_inference_failure_err(
+ body_id,
+ span,
+ subst,
+ ErrorCode::E0284,
+ true,
+ );
+ err.note(&format!("cannot satisfy `{}`", predicate));
+ err
+ } else {
+ todo!();
+ }
+ }
_ => {
if self.tcx.sess.has_errors().is_some() || self.is_tainted_by_errors() {
return;
From b33955a0ef3b38f2c9448b1dcab82c31b097438e Mon Sep 17 00:00:00 2001
From: Katherine Philip <kurerunoshikaku@yahoo.com>
Date: Wed, 13 Jul 2022 10:25:58 -0700
Subject: [PATCH 2/4] Add checks & fallback branch
---
.../src/traits/error_reporting/mod.rs | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 8396df4a243..925e8012819 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -2157,6 +2157,9 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
}
ty::PredicateKind::ConstEvaluatable(data) => {
+ if predicate.references_error() || self.is_tainted_by_errors() {
+ return;
+ }
let subst = data.substs.iter().find(|g| g.has_infer_types_or_consts());
if let Some(subst) = subst {
let mut err = self.emit_inference_failure_err(
@@ -2169,7 +2172,16 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
err.note(&format!("cannot satisfy `{}`", predicate));
err
} else {
- todo!();
+ // If we can't find a substitution, just print a generic error
+ let mut err = struct_span_err!(
+ self.tcx.sess,
+ span,
+ E0284,
+ "type annotations needed: cannot satisfy `{}`",
+ predicate,
+ );
+ err.span_label(span, &format!("cannot satisfy `{}`", predicate));
+ err
}
}
_ => {
From 083bd7cb1ddf02820caf6cd3e04330458d0624b8 Mon Sep 17 00:00:00 2001
From: Katherine Philip <kurerunoshikaku@yahoo.com>
Date: Wed, 13 Jul 2022 10:27:19 -0700
Subject: [PATCH 3/4] Remove predicate note
---
.../rustc_trait_selection/src/traits/error_reporting/mod.rs | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 925e8012819..5f8560902f5 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -2162,14 +2162,13 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> {
}
let subst = data.substs.iter().find(|g| g.has_infer_types_or_consts());
if let Some(subst) = subst {
- let mut err = self.emit_inference_failure_err(
+ let err = self.emit_inference_failure_err(
body_id,
span,
subst,
ErrorCode::E0284,
true,
);
- err.note(&format!("cannot satisfy `{}`", predicate));
err
} else {
// If we can't find a substitution, just print a generic error
From 96d34dc9ff557c189fef19cb00b36f5cd5c7ac49 Mon Sep 17 00:00:00 2001
From: Katherine Philip <kurerunoshikaku@yahoo.com>
Date: Wed, 13 Jul 2022 17:28:11 -0700
Subject: [PATCH 4/4] Update tests
---
.../generic_const_exprs/object-safety-ok-infer-err.rs | 1 -
.../object-safety-ok-infer-err.stderr | 10 +++++++---
.../parent_generics_of_encoding_impl_trait.rs | 2 +-
.../parent_generics_of_encoding_impl_trait.stderr | 4 ++--
4 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.rs b/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.rs
index c6c196db6f2..79e9834b54e 100644
--- a/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.rs
+++ b/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.rs
@@ -16,7 +16,6 @@ fn use_dyn<const N: usize>(v: &dyn Foo<N>) where [u8; N + 1]: Sized {
}
fn main() {
- // FIXME(generic_const_exprs): Improve the error message here.
use_dyn(&());
//~^ ERROR type annotations needed
}
diff --git a/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.stderr b/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.stderr
index ce75314ada7..59e9fee1eaf 100644
--- a/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.stderr
+++ b/src/test/ui/const-generics/generic_const_exprs/object-safety-ok-infer-err.stderr
@@ -1,14 +1,18 @@
-error[E0284]: type annotations needed: cannot satisfy `the constant `use_dyn::<{_: usize}>::{constant#0}` can be evaluated`
- --> $DIR/object-safety-ok-infer-err.rs:20:5
+error[E0284]: type annotations needed
+ --> $DIR/object-safety-ok-infer-err.rs:19:5
|
LL | use_dyn(&());
- | ^^^^^^^ cannot satisfy `the constant `use_dyn::<{_: usize}>::{constant#0}` can be evaluated`
+ | ^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `use_dyn`
|
note: required by a bound in `use_dyn`
--> $DIR/object-safety-ok-infer-err.rs:14:55
|
LL | fn use_dyn<const N: usize>(v: &dyn Foo<N>) where [u8; N + 1]: Sized {
| ^^^^^ required by this bound in `use_dyn`
+help: consider specifying the generic argument
+ |
+LL | use_dyn::<N>(&());
+ | +++++
error: aborting due to previous error
diff --git a/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.rs b/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.rs
index ed81c01bb17..7a78e0f109c 100644
--- a/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.rs
+++ b/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.rs
@@ -7,5 +7,5 @@ extern crate generics_of_parent_impl_trait;
fn main() {
// check for `impl Trait<{ const }>` which has a parent of a `DefKind::TyParam`
generics_of_parent_impl_trait::foo([()]);
- //~^ error: type annotations needed:
+ //~^ error: type annotations needed
}
diff --git a/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.stderr b/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.stderr
index 99085711513..87ff7babe71 100644
--- a/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.stderr
+++ b/src/test/ui/const-generics/parent_generics_of_encoding_impl_trait.stderr
@@ -1,8 +1,8 @@
-error[E0284]: type annotations needed: cannot satisfy `the constant `foo::{opaque#0}::{constant#0}` can be evaluated`
+error[E0284]: type annotations needed
--> $DIR/parent_generics_of_encoding_impl_trait.rs:9:5
|
LL | generics_of_parent_impl_trait::foo([()]);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot satisfy `the constant `foo::{opaque#0}::{constant#0}` can be evaluated`
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer the value of const parameter `N` declared on the function `foo`
|
note: required by a bound in `foo`
--> $DIR/auxiliary/generics_of_parent_impl_trait.rs:6:48