better ObligationCause for normalization errors in can_type_implement_copy

This commit is contained in:
Michael Goulet 2022-02-06 13:03:28 -08:00
parent 3d127e2040
commit 8ba74369c2
8 changed files with 71 additions and 22 deletions

View File

@ -51,7 +51,7 @@
use rustc_span::symbol::{kw, sym, Ident, Symbol};
use rustc_span::{BytePos, InnerSpan, MultiSpan, Span};
use rustc_target::abi::VariantIdx;
use rustc_trait_selection::traits::misc::can_type_implement_copy;
use rustc_trait_selection::traits::{self, misc::can_type_implement_copy};
use crate::nonstandard_style::{method_context, MethodLateContext};
@ -764,7 +764,14 @@ fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) {
if ty.is_copy_modulo_regions(cx.tcx.at(item.span), param_env) {
return;
}
if can_type_implement_copy(cx.tcx, param_env, ty).is_ok() {
if can_type_implement_copy(
cx.tcx,
param_env,
ty,
traits::ObligationCause::misc(item.span, item.hir_id()),
)
.is_ok()
{
cx.struct_span_lint(MISSING_COPY_IMPLEMENTATIONS, item.span, |lint| {
lint.build(
"type could implement `Copy`; consider adding `impl \

View File

@ -20,6 +20,7 @@ pub fn can_type_implement_copy<'tcx>(
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
self_type: Ty<'tcx>,
cause: ObligationCause<'tcx>,
) -> Result<(), CopyImplementationError<'tcx>> {
// FIXME: (@jroesch) float this code up
tcx.infer_ctxt().enter(|infcx| {
@ -49,9 +50,8 @@ pub fn can_type_implement_copy<'tcx>(
continue;
}
let span = tcx.def_span(field.did);
let cause = ObligationCause::dummy_with_span(span);
let ctx = traits::FulfillmentContext::new();
match traits::fully_normalize(&infcx, ctx, cause, param_env, ty) {
match traits::fully_normalize(&infcx, ctx, cause.clone(), param_env, ty) {
Ok(ty) => {
if !infcx.type_is_copy_modulo_regions(param_env, ty, span) {
infringing.push(field);

View File

@ -74,7 +74,8 @@ fn visit_implementation_of_copy(tcx: TyCtxt<'_>, impl_did: LocalDefId) {
debug!("visit_implementation_of_copy: self_type={:?} (free)", self_type);
match can_type_implement_copy(tcx, param_env, self_type) {
let cause = traits::ObligationCause::misc(span, impl_hir_id);
match can_type_implement_copy(tcx, param_env, self_type, cause) {
Ok(()) => {}
Err(CopyImplementationError::InfrigingFields(fields)) => {
let item = tcx.hir().expect_item(impl_did);

View File

@ -1,17 +1,17 @@
#[derive(Clone, Copy)]
//~^ ERROR the trait `Copy` may not be implemented for this type
//~| ERROR `i32` is not an iterator
struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
//~^ ERROR cannot find type `NotDefined` in this scope
//~| ERROR cannot find type `NotDefined` in this scope
//~| ERROR cannot find type `N` in this scope
//~| ERROR cannot find type `N` in this scope
//~| ERROR `i32` is not an iterator
#[derive(Clone, Copy)]
//~^ ERROR the trait `Copy` may not be implemented for this type
//~| ERROR `i32` is not an iterator
struct Bar<T>(T, N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
//~^ ERROR cannot find type `NotDefined` in this scope
//~| ERROR cannot find type `N` in this scope
//~| ERROR `i32` is not an iterator
fn main() {}

View File

@ -1,5 +1,5 @@
error[E0412]: cannot find type `N` in this scope
--> $DIR/issue-50480.rs:3:12
--> $DIR/issue-50480.rs:4:12
|
LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| -^ not found in this scope
@ -7,13 +7,13 @@ LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| help: you might be missing a type parameter: `<N>`
error[E0412]: cannot find type `NotDefined` in this scope
--> $DIR/issue-50480.rs:3:15
--> $DIR/issue-50480.rs:4:15
|
LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| ^^^^^^^^^^ not found in this scope
error[E0412]: cannot find type `N` in this scope
--> $DIR/issue-50480.rs:3:12
--> $DIR/issue-50480.rs:4:12
|
LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| -^ not found in this scope
@ -21,7 +21,7 @@ LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| help: you might be missing a type parameter: `<N>`
error[E0412]: cannot find type `NotDefined` in this scope
--> $DIR/issue-50480.rs:3:15
--> $DIR/issue-50480.rs:4:15
|
LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| - ^^^^^^^^^^ not found in this scope
@ -29,7 +29,7 @@ LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| help: you might be missing a type parameter: `<NotDefined>`
error[E0412]: cannot find type `N` in this scope
--> $DIR/issue-50480.rs:12:18
--> $DIR/issue-50480.rs:13:18
|
LL | struct Bar<T>(T, N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| - ^
@ -46,26 +46,27 @@ LL | struct Bar<T, N>(T, N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, Strin
| +++
error[E0412]: cannot find type `NotDefined` in this scope
--> $DIR/issue-50480.rs:12:21
--> $DIR/issue-50480.rs:13:21
|
LL | struct Bar<T>(T, N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| ^^^^^^^^^^ not found in this scope
error[E0277]: `i32` is not an iterator
--> $DIR/issue-50480.rs:3:27
--> $DIR/issue-50480.rs:1:17
|
LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| ^^^^^^^^^^^^^^^^^^^^^^^ `i32` is not an iterator
LL | #[derive(Clone, Copy)]
| ^^^^ `i32` is not an iterator
|
= help: the trait `Iterator` is not implemented for `i32`
= note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
= note: this error originates in the derive macro `Copy` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0204]: the trait `Copy` may not be implemented for this type
--> $DIR/issue-50480.rs:1:17
|
LL | #[derive(Clone, Copy)]
| ^^^^
LL |
...
LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| -------- ------ this field does not implement `Copy`
| |
@ -74,20 +75,21 @@ LL | struct Foo(N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
= note: this error originates in the derive macro `Copy` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0277]: `i32` is not an iterator
--> $DIR/issue-50480.rs:12:33
--> $DIR/issue-50480.rs:10:17
|
LL | struct Bar<T>(T, N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| ^^^^^^^^^^^^^^^^^^^^^^^ `i32` is not an iterator
LL | #[derive(Clone, Copy)]
| ^^^^ `i32` is not an iterator
|
= help: the trait `Iterator` is not implemented for `i32`
= note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
= note: this error originates in the derive macro `Copy` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0204]: the trait `Copy` may not be implemented for this type
--> $DIR/issue-50480.rs:10:17
|
LL | #[derive(Clone, Copy)]
| ^^^^
LL |
...
LL | struct Bar<T>(T, N, NotDefined, <i32 as Iterator>::Item, Vec<i32>, String);
| -------- ------ this field does not implement `Copy`
| |

View File

@ -0,0 +1,25 @@
trait TraitFoo {
type Bar;
}
struct Foo<T>
where
T: TraitFoo,
{
inner: T::Bar,
}
impl<T> Clone for Foo<T>
where
T: TraitFoo,
T::Bar: Clone,
{
fn clone(&self) -> Self {
Self { inner: self.inner.clone() }
}
}
impl<T> Copy for Foo<T> {}
//~^ ERROR the trait bound `T: TraitFoo` is not satisfied
fn main() {}

View File

@ -0,0 +1,14 @@
error[E0277]: the trait bound `T: TraitFoo` is not satisfied
--> $DIR/copy-impl-cannot-normalize.rs:22:1
|
LL | impl<T> Copy for Foo<T> {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `TraitFoo` is not implemented for `T`
|
help: consider restricting type parameter `T`
|
LL | impl<T: TraitFoo> Copy for Foo<T> {}
| ++++++++++
error: aborting due to previous error
For more information about this error, try `rustc --explain E0277`.

View File

@ -199,7 +199,7 @@ fn check_fn(
let sugg = |diag: &mut DiagnosticBuilder<'_>| {
if let ty::Adt(def, ..) = ty.kind() {
if let Some(span) = cx.tcx.hir().span_if_local(def.did) {
if can_type_implement_copy(cx.tcx, cx.param_env, ty).is_ok() {
if can_type_implement_copy(cx.tcx, cx.param_env, ty, traits::ObligationCause::dummy_with_span(span)).is_ok() {
diag.span_help(span, "consider marking this type as `Copy`");
}
}