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Tweak unsatisfied HRTB errors
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@estebank
estebank committed Sep 16, 2019
1 parent a44881d commit 0a985f2
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Showing 11 changed files with 148 additions and 62 deletions.
53 changes: 31 additions & 22 deletions src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
View file
Expand Up @@ -192,23 +192,28 @@ impl NiceRegionError<'me, 'tcx> {
vid, sub_placeholder, sup_placeholder, trait_def_id, expected_substs, actual_substs
);

let mut err = self.tcx().sess.struct_span_err(
cause.span(self.tcx()),
&format!(
"implementation of `{}` is not general enough",
self.tcx().def_path_str(trait_def_id),
),
let span = cause.span(self.tcx());
let msg = format!(
"implementation of `{}` is not general enough",
self.tcx().def_path_str(trait_def_id),
);
let mut err = self.tcx().sess.struct_span_err(span, &msg);
err.span_label(
self.tcx().def_span(trait_def_id),
format!("trait `{}` defined here", self.tcx().def_path_str(trait_def_id)),
);

match cause.code {
ObligationCauseCode::ItemObligation(def_id) => {
err.note(&format!(
"Due to a where-clause on `{}`,",
self.tcx().def_path_str(def_id),
));
}
_ => (),
}
let leading_ellipsis = if let ObligationCauseCode::ItemObligation(def_id) = cause.code {
err.span_label(span, "doesn't satisfy where-clause");
err.span_label(
self.tcx().def_span(def_id),
&format!("due to a where-clause on `{}`...", self.tcx().def_path_str(def_id)),
);
true
} else {
err.span_label(span, &msg);
false
};

let expected_trait_ref = self.infcx.resolve_vars_if_possible(&ty::TraitRef {
def_id: trait_def_id,
Expand Down Expand Up @@ -295,6 +300,7 @@ impl NiceRegionError<'me, 'tcx> {
expected_has_vid,
actual_has_vid,
any_self_ty_has_vid,
leading_ellipsis,
);

err
Expand All @@ -318,6 +324,7 @@ impl NiceRegionError<'me, 'tcx> {
expected_has_vid: Option<usize>,
actual_has_vid: Option<usize>,
any_self_ty_has_vid: bool,
leading_ellipsis: bool,
) {
// HACK(eddyb) maybe move this in a more central location.
#[derive(Copy, Clone)]
Expand Down Expand Up @@ -392,13 +399,15 @@ impl NiceRegionError<'me, 'tcx> {

let mut note = if passive_voice {
format!(
"`{}` would have to be implemented for the type `{}`",
"{}`{}` would have to be implemented for the type `{}`",
if leading_ellipsis { "..." } else { "" },
expected_trait_ref,
expected_trait_ref.map(|tr| tr.self_ty()),
)
} else {
format!(
"`{}` must implement `{}`",
"{}`{}` must implement `{}`",
if leading_ellipsis { "..." } else { "" },
expected_trait_ref.map(|tr| tr.self_ty()),
expected_trait_ref,
)
Expand All @@ -407,20 +416,20 @@ impl NiceRegionError<'me, 'tcx> {
match (has_sub, has_sup) {
(Some(n1), Some(n2)) => {
let _ = write!(note,
", for any two lifetimes `'{}` and `'{}`",
", for any two lifetimes `'{}` and `'{}`...",
std::cmp::min(n1, n2),
std::cmp::max(n1, n2),
);
}
(Some(n), _) | (_, Some(n)) => {
let _ = write!(note,
", for any lifetime `'{}`",
", for any lifetime `'{}`...",
n,
);
}
(None, None) => if let Some(n) = expected_has_vid {
let _ = write!(note,
", for some specific lifetime `'{}`",
", for some specific lifetime `'{}`...",
n,
);
},
Expand All @@ -439,13 +448,13 @@ impl NiceRegionError<'me, 'tcx> {

let mut note = if passive_voice {
format!(
"but `{}` is actually implemented for the type `{}`",
"...but `{}` is actually implemented for the type `{}`",
actual_trait_ref,
actual_trait_ref.map(|tr| tr.self_ty()),
)
} else {
format!(
"but `{}` actually implements `{}`",
"...but `{}` actually implements `{}`",
actual_trait_ref.map(|tr| tr.self_ty()),
actual_trait_ref,
)
Expand Down
18 changes: 12 additions & 6 deletions src/test/ui/generator/auto-trait-regions.stderr
View file
@@ -1,20 +1,26 @@
error: implementation of `Foo` is not general enough
--> $DIR/auto-trait-regions.rs:30:5
|
LL | auto trait Foo {}
| ----------------- trait `Foo` defined here
...
LL | assert_foo(gen);
| ^^^^^^^^^^
| ^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo` would have to be implemented for the type `&'0 OnlyFooIfStaticRef`, for any lifetime `'0`
= note: but `Foo` is actually implemented for the type `&'1 OnlyFooIfStaticRef`, for some specific lifetime `'1`
= note: `Foo` would have to be implemented for the type `&'0 OnlyFooIfStaticRef`, for any lifetime `'0`...
= note: ...but `Foo` is actually implemented for the type `&'1 OnlyFooIfStaticRef`, for some specific lifetime `'1`

error: implementation of `Foo` is not general enough
--> $DIR/auto-trait-regions.rs:48:5
|
LL | auto trait Foo {}
| ----------------- trait `Foo` defined here
...
LL | assert_foo(gen);
| ^^^^^^^^^^
| ^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo` would have to be implemented for the type `A<'0, '1>`, for any two lifetimes `'0` and `'1`
= note: but `Foo` is actually implemented for the type `A<'_, '2>`, for some specific lifetime `'2`
= note: `Foo` would have to be implemented for the type `A<'0, '1>`, for any two lifetimes `'0` and `'1`...
= note: ...but `Foo` is actually implemented for the type `A<'_, '2>`, for some specific lifetime `'2`

error: aborting due to 2 previous errors

16 changes: 16 additions & 0 deletions src/test/ui/hrtb/due-to-where-clause.rs
View file
@@ -0,0 +1,16 @@
// ignore-compare-mode-nll
// ^ This code works in nll mode.

fn main() {
test::<FooS>(&mut 42); //~ ERROR implementation of `Foo` is not general enough
}

trait Foo<'a> {}

struct FooS<'a> {
data: &'a mut u32,
}

impl<'a, 'b: 'a> Foo<'b> for FooS<'a> {}

fn test<'a, F>(data: &'a mut u32) where F: for<'b> Foo<'b> {}
17 changes: 17 additions & 0 deletions src/test/ui/hrtb/due-to-where-clause.stderr
View file
@@ -0,0 +1,17 @@
error: implementation of `Foo` is not general enough
--> $DIR/due-to-where-clause.rs:5:5
|
LL | test::<FooS>(&mut 42);
| ^^^^^^^^^^^^ doesn't satisfy where-clause
...
LL | trait Foo<'a> {}
| ---------------- trait `Foo` defined here
...
LL | fn test<'a, F>(data: &'a mut u32) where F: for<'b> Foo<'b> {}
| ------------------------------------------------------------- due to a where-clause on `test`...
|
= note: ...`FooS<'_>` must implement `Foo<'0>`, for any lifetime `'0`...
= note: ...but `FooS<'_>` actually implements `Foo<'1>`, for some specific lifetime `'1`

error: aborting due to previous error

9 changes: 6 additions & 3 deletions src/test/ui/hrtb/hrtb-cache-issue-54302.stderr
View file
@@ -1,11 +1,14 @@
error: implementation of `Deserialize` is not general enough
--> $DIR/hrtb-cache-issue-54302.rs:19:5
|
LL | trait Deserialize<'de> {}
| ------------------------- trait `Deserialize` defined here
...
LL | assert_deserialize_owned::<&'static str>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Deserialize` is not general enough
|
= note: `&'static str` must implement `Deserialize<'0>`, for any lifetime `'0`
= note: but `&str` actually implements `Deserialize<'1>`, for some specific lifetime `'1`
= note: `&'static str` must implement `Deserialize<'0>`, for any lifetime `'0`...
= note: ...but `&str` actually implements `Deserialize<'1>`, for some specific lifetime `'1`

error: aborting due to previous error

14 changes: 10 additions & 4 deletions src/test/ui/hrtb/issue-30786.migrate.stderr
View file
@@ -1,11 +1,17 @@
error: implementation of `Stream` is not general enough
--> $DIR/issue-30786.rs:108:22
|
LL | let map = source.map(|x: &_| x);
| ^^^
LL | / pub trait Stream {
LL | | type Item;
LL | | fn next(self) -> Option<Self::Item>;
LL | | }
| |_- trait `Stream` defined here
...
LL | let map = source.map(|x: &_| x);
| ^^^ implementation of `Stream` is not general enough
|
= note: `Stream` would have to be implemented for the type `&'0 mut Map<Repeat, [closure@$DIR/issue-30786.rs:108:26: 108:35]>`, for any lifetime `'0`
= note: but `Stream` is actually implemented for the type `&'1 mut Map<Repeat, [closure@$DIR/issue-30786.rs:108:26: 108:35]>`, for some specific lifetime `'1`
= note: `Stream` would have to be implemented for the type `&'0 mut Map<Repeat, [closure@$DIR/issue-30786.rs:108:26: 108:35]>`, for any lifetime `'0`...
= note: ...but `Stream` is actually implemented for the type `&'1 mut Map<Repeat, [closure@$DIR/issue-30786.rs:108:26: 108:35]>`, for some specific lifetime `'1`

error: aborting due to previous error

4 changes: 2 additions & 2 deletions src/test/ui/hrtb/issue-30786.nll.stderr
View file
@@ -1,11 +1,11 @@
error: higher-ranked subtype error
--> $DIR/issue-30786.rs:112:18
--> $DIR/issue-30786.rs:113:18
|
LL | let filter = map.filter(|x: &_| true);
| ^^^^^^^^^^^^^^^^^^^^^^^^

error: higher-ranked subtype error
--> $DIR/issue-30786.rs:114:17
--> $DIR/issue-30786.rs:115:17
|
LL | let count = filter.count(); // Assert that we still have a valid stream.
| ^^^^^^^^^^^^^^
Expand Down
3 changes: 2 additions & 1 deletion src/test/ui/hrtb/issue-30786.rs
View file
Expand Up @@ -16,7 +16,7 @@

//[nll]compile-flags: -Z borrowck=mir

pub trait Stream {
pub trait Stream { //[migrate]~ NOTE trait `Stream` defined here
type Item;
fn next(self) -> Option<Self::Item>;
}
Expand Down Expand Up @@ -109,6 +109,7 @@ fn main() {
//[migrate]~^ ERROR implementation of `Stream` is not general enough
//[migrate]~| NOTE `Stream` would have to be implemented for the type `&'0 mut Map
//[migrate]~| NOTE but `Stream` is actually implemented for the type `&'1
//[migrate]~| NOTE implementation of `Stream` is not general enough
let filter = map.filter(|x: &_| true);
//[nll]~^ ERROR higher-ranked subtype error
let count = filter.count(); // Assert that we still have a valid stream.
Expand Down
54 changes: 37 additions & 17 deletions src/test/ui/issues/issue-54302-cases.stderr
View file
@@ -1,38 +1,58 @@
error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:63:5
|
LL | <u32 as RefFoo<u32>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: `Foo<'static, u32>` would have to be implemented for the type `&'0 u32`, for any lifetime `'0`
= note: but `Foo<'_, u32>` is actually implemented for the type `&'1 u32`, for some specific lifetime `'1`
LL | / trait Foo<'x, T> {
LL | | fn foo(self) -> &'x T;
LL | | }
| |_- trait `Foo` defined here
...
LL | <u32 as RefFoo<u32>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, u32>` would have to be implemented for the type `&'0 u32`, for any lifetime `'0`...
= note: ...but `Foo<'_, u32>` is actually implemented for the type `&'1 u32`, for some specific lifetime `'1`

error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:69:5
|
LL | <i32 as RefFoo<i32>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | / trait Foo<'x, T> {
LL | | fn foo(self) -> &'x T;
LL | | }
| |_- trait `Foo` defined here
...
LL | <i32 as RefFoo<i32>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, i32>` would have to be implemented for the type `&'0 i32`, for any lifetime `'0`
= note: but `Foo<'_, i32>` is actually implemented for the type `&'1 i32`, for some specific lifetime `'1`
= note: `Foo<'static, i32>` would have to be implemented for the type `&'0 i32`, for any lifetime `'0`...
= note: ...but `Foo<'_, i32>` is actually implemented for the type `&'1 i32`, for some specific lifetime `'1`

error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:75:5
|
LL | <u64 as RefFoo<u64>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | / trait Foo<'x, T> {
LL | | fn foo(self) -> &'x T;
LL | | }
| |_- trait `Foo` defined here
...
LL | <u64 as RefFoo<u64>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, u64>` would have to be implemented for the type `&'0 u64`, for any lifetime `'0`
= note: but `Foo<'_, u64>` is actually implemented for the type `&'1 u64`, for some specific lifetime `'1`
= note: `Foo<'static, u64>` would have to be implemented for the type `&'0 u64`, for any lifetime `'0`...
= note: ...but `Foo<'_, u64>` is actually implemented for the type `&'1 u64`, for some specific lifetime `'1`

error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:81:5
|
LL | <i64 as RefFoo<i64>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | / trait Foo<'x, T> {
LL | | fn foo(self) -> &'x T;
LL | | }
| |_- trait `Foo` defined here
...
LL | <i64 as RefFoo<i64>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, i64>` would have to be implemented for the type `&'0 i64`, for any lifetime `'0`
= note: but `Foo<'_, i64>` is actually implemented for the type `&'1 i64`, for some specific lifetime `'1`
= note: `Foo<'static, i64>` would have to be implemented for the type `&'0 i64`, for any lifetime `'0`...
= note: ...but `Foo<'_, i64>` is actually implemented for the type `&'1 i64`, for some specific lifetime `'1`

error: aborting due to 4 previous errors

9 changes: 6 additions & 3 deletions src/test/ui/issues/issue-54302.stderr
View file
@@ -1,11 +1,14 @@
error: implementation of `Deserialize` is not general enough
--> $DIR/issue-54302.rs:13:5
|
LL | trait Deserialize<'de> {}
| ------------------------- trait `Deserialize` defined here
...
LL | assert_deserialize_owned::<&'static str>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Deserialize` is not general enough
|
= note: `&'static str` must implement `Deserialize<'0>`, for any lifetime `'0`
= note: but `&str` actually implements `Deserialize<'1>`, for some specific lifetime `'1`
= note: `&'static str` must implement `Deserialize<'0>`, for any lifetime `'0`...
= note: ...but `&str` actually implements `Deserialize<'1>`, for some specific lifetime `'1`

error: aborting due to previous error

13 changes: 9 additions & 4 deletions src/test/ui/issues/issue-55731.stderr
View file
@@ -1,11 +1,16 @@
error: implementation of `DistributedIteratorMulti` is not general enough
--> $DIR/issue-55731.rs:48:5
|
LL | multi(Map {
| ^^^^^
LL | / trait DistributedIteratorMulti<Source> {
LL | | type Item;
LL | | }
| |_- trait `DistributedIteratorMulti` defined here
...
LL | multi(Map {
| ^^^^^ implementation of `DistributedIteratorMulti` is not general enough
|
= note: `DistributedIteratorMulti<&'0 ()>` would have to be implemented for the type `Cloned<&()>`, for any lifetime `'0`
= note: but `DistributedIteratorMulti<&'1 ()>` is actually implemented for the type `Cloned<&'1 ()>`, for some specific lifetime `'1`
= note: `DistributedIteratorMulti<&'0 ()>` would have to be implemented for the type `Cloned<&()>`, for any lifetime `'0`...
= note: ...but `DistributedIteratorMulti<&'1 ()>` is actually implemented for the type `Cloned<&'1 ()>`, for some specific lifetime `'1`

error: aborting due to previous error

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