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Add correct span for unsized types #143580

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48 changes: 48 additions & 0 deletions compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
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I have some questions about this two places

rust/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs

Lines 794 to 798 in c7f662b

if let Some(pos) = snippet.find(&self_ty) {
let start = span.lo() + BytePos(pos as u32);
let end = start + BytePos(self_ty.len() as u32);
return Some(Span::new(start, end, span.ctxt(), span.parent()));
}

rust/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs

Lines 811 to 815 in c7f662b

if let Some(pos) = snippet.find(&core_type) {
let start = span.lo() + BytePos(pos as u32);
let end = start + BytePos(core_type.len() as u32);
return Some(Span::new(start, end, span.ctxt(), span.parent()));
}

I feel like its a code duplication but I have no idea how to improve it, so i just leaved like this, if there any better way to write it, I`d love to learn best practices

Original file line number Diff line number Diff line change
Expand Up @@ -269,6 +269,12 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
(err_msg, None)
};

if tcx.is_lang_item(leaf_trait_predicate.def_id(), LangItem::Sized) {
if let Some(refined_span) = self.report_sized_item(span, leaf_trait_predicate) {
span = refined_span;
}
}

let mut err = struct_span_code_err!(self.dcx(), span, E0277, "{}", err_msg);
*err.long_ty_path() = long_ty_file;

Expand Down Expand Up @@ -769,6 +775,48 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
applied_do_not_recommend
}

fn report_sized_item(
&self,
span: Span,
trait_pred: ty::PolyTraitPredicate<'tcx>,
) -> Option<Span> {
let source_map = self.tcx.sess.source_map();
let snippet = source_map.span_to_snippet(span).ok()?;

// Skip macro
if snippet.contains('!') {
return None;
}

let self_ty = trait_pred.skip_binder().self_ty().to_string();

// Try to find the exact type in the source code
if let Some(pos) = snippet.find(&self_ty) {
let start = span.lo() + BytePos(pos as u32);
let end = start + BytePos(self_ty.len() as u32);
return Some(Span::new(start, end, span.ctxt(), span.parent()));
}

// Sanity check if exact match fails
let mut core_type = self_ty.as_str();
while core_type.starts_with('[') && core_type.ends_with(']') {
core_type = &core_type[1..core_type.len() - 1].trim();
if let Some(pos) = core_type.find(';') {
core_type = &core_type[..pos].trim();
}
}

// Try to find core type
if core_type != self_ty && !core_type.is_empty() {
if let Some(pos) = snippet.find(&core_type) {
let start = span.lo() + BytePos(pos as u32);
let end = start + BytePos(core_type.len() as u32);
return Some(Span::new(start, end, span.ctxt(), span.parent()));
}
}
None
}

fn report_host_effect_error(
&self,
predicate: ty::Binder<'tcx, ty::HostEffectPredicate<'tcx>>,
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/abi/debug.generic.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -876,10 +876,10 @@ LL | type TestAbiNeSign = (fn(i32), fn(u32));
| ^^^^^^^^^^^^^^^^^^

error[E0277]: the size for values of type `str` cannot be known at compilation time
--> $DIR/debug.rs:68:46
--> $DIR/debug.rs:68:47
|
LL | type TestAbiEqNonsense = (fn((str, str)), fn((str, str)));
| ^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= note: only the last element of a tuple may have a dynamically sized type
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/abi/debug.riscv64.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -876,10 +876,10 @@ LL | type TestAbiNeSign = (fn(i32), fn(u32));
| ^^^^^^^^^^^^^^^^^^

error[E0277]: the size for values of type `str` cannot be known at compilation time
--> $DIR/debug.rs:68:46
--> $DIR/debug.rs:68:47
|
LL | type TestAbiEqNonsense = (fn((str, str)), fn((str, str)));
| ^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= note: only the last element of a tuple may have a dynamically sized type
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/associated-types/defaults-wf.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
--> $DIR/defaults-wf.rs:7:15
--> $DIR/defaults-wf.rs:7:19
|
LL | type Ty = Vec<[u8]>;
| ^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `[u8]`
note: required by an implicit `Sized` bound in `Vec`
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/associated-types/issue-20005.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `Self` cannot be known at compilation time
--> $DIR/issue-20005.rs:10:49
--> $DIR/issue-20005.rs:10:54
|
LL | ) -> <Dst as From<Self>>::Result where Dst: From<Self> {
| ^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^ doesn't have a size known at compile-time
|
note: required by an implicit `Sized` bound in `From`
--> $DIR/issue-20005.rs:1:12
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/associated-types/trait-with-supertraits-needing-sized-self.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `Self` cannot be known at compilation time
--> $DIR/trait-with-supertraits-needing-sized-self.rs:3:22
--> $DIR/trait-with-supertraits-needing-sized-self.rs:3:33
|
LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self> + Div<Output=Self> {}
| ^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^ doesn't have a size known at compile-time
|
note: required by an implicit `Sized` bound in `Add`
--> $SRC_DIR/core/src/ops/arith.rs:LL:COL
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/cast/unsized-union-ice.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
--> $DIR/unsized-union-ice.rs:6:10
--> $DIR/unsized-union-ice.rs:6:33
|
LL | val: std::mem::ManuallyDrop<[u8]>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^ doesn't have a size known at compile-time
|
= help: within `ManuallyDrop<[u8]>`, the trait `Sized` is not implemented for `[u8]`
note: required because it appears within the type `ManuallyDrop<[u8]>`
Expand Down
36 changes: 18 additions & 18 deletions tests/ui/closures/closure-return-type-must-be-sized.stderr
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Original file line number Diff line number Diff line change
@@ -1,17 +1,17 @@
error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:54:5
--> $DIR/closure-return-type-must-be-sized.rs:54:22
|
LL | a::foo::<fn() -> dyn A>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:55:14
--> $DIR/closure-return-type-must-be-sized.rs:55:22
|
LL | a::bar::<fn() -> dyn A, _>();
| ^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`
Expand All @@ -22,28 +22,28 @@ LL | pub fn bar<F: FnOnce() -> R, R: ?Sized>() {}
| ^^^^^^^^^^^^^ required by this bound in `bar`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:56:5
--> $DIR/closure-return-type-must-be-sized.rs:56:22
|
LL | a::baz::<fn() -> dyn A>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:61:5
--> $DIR/closure-return-type-must-be-sized.rs:61:22
|
LL | b::foo::<fn() -> dyn A>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:62:14
--> $DIR/closure-return-type-must-be-sized.rs:62:22
|
LL | b::bar::<fn() -> dyn A, _>();
| ^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`
Expand All @@ -54,28 +54,28 @@ LL | pub fn bar<F: Fn() -> R, R: ?Sized>() {}
| ^^^^^^^^^ required by this bound in `bar`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:63:5
--> $DIR/closure-return-type-must-be-sized.rs:63:22
|
LL | b::baz::<fn() -> dyn A>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:68:5
--> $DIR/closure-return-type-must-be-sized.rs:68:22
|
LL | c::foo::<fn() -> dyn A>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:69:14
--> $DIR/closure-return-type-must-be-sized.rs:69:22
|
LL | c::bar::<fn() -> dyn A, _>();
| ^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`
Expand All @@ -86,10 +86,10 @@ LL | pub fn bar<F: FnMut() -> R, R: ?Sized>() {}
| ^^^^^^^^^^^^ required by this bound in `bar`

error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
--> $DIR/closure-return-type-must-be-sized.rs:70:5
--> $DIR/closure-return-type-must-be-sized.rs:70:22
|
LL | c::baz::<fn() -> dyn A>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
= note: required because it appears within the type `fn() -> dyn A`
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/closures/missing-body.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,10 @@ LL | fn main() { |b: [str; _]| {}; }
| ^ not allowed in type signatures

error[E0277]: the size for values of type `str` cannot be known at compilation time
--> $DIR/missing-body.rs:5:17
--> $DIR/missing-body.rs:5:18
|
LL | fn main() { |b: [str; _]| {}; }
| ^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= note: slice and array elements must have `Sized` type
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/consts/const-unsized.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -26,10 +26,10 @@ LL | static STATIC_1: dyn Debug + Sync = *(&1 as &(dyn Debug + Sync));
= note: statics and constants must have a statically known size

error[E0277]: the size for values of type `str` cannot be known at compilation time
--> $DIR/const-unsized.rs:15:1
--> $DIR/const-unsized.rs:15:20
|
LL | static STATIC_BAR: str = *"bar";
| ^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= note: statics and constants must have a statically known size
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/consts/dont-ctfe-unsized-initializer.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `str` cannot be known at compilation time
--> $DIR/dont-ctfe-unsized-initializer.rs:1:1
--> $DIR/dont-ctfe-unsized-initializer.rs:1:11
|
LL | static S: str = todo!();
| ^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= note: statics and constants must have a statically known size
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/dst/dst-sized-trait-param.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `[isize]` cannot be known at compilation time
--> $DIR/dst-sized-trait-param.rs:7:6
--> $DIR/dst-sized-trait-param.rs:7:10
|
LL | impl Foo<[isize]> for usize { }
| ^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `[isize]`
note: required by an implicit `Sized` bound in `Foo`
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/dyn-compatibility/supertrait-mentions-Self.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `Self` cannot be known at compilation time
--> $DIR/supertrait-mentions-Self.rs:8:13
--> $DIR/supertrait-mentions-Self.rs:8:17
|
LL | trait Baz : Bar<Self> {
| ^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^ doesn't have a size known at compile-time
|
note: required by an implicit `Sized` bound in `Bar`
--> $DIR/supertrait-mentions-Self.rs:4:11
Expand Down
8 changes: 4 additions & 4 deletions tests/ui/extern/extern-types-unsized.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -38,10 +38,10 @@ LL | fn assert_sized<T: ?Sized>() {}
| ++++++++

error[E0277]: the size for values of type `A` cannot be known at compilation time
--> $DIR/extern-types-unsized.rs:28:20
--> $DIR/extern-types-unsized.rs:28:24
|
LL | assert_sized::<Bar<A>>();
| ^^^^^^ doesn't have a size known at compile-time
| ^ doesn't have a size known at compile-time
|
= help: within `Bar<A>`, the trait `Sized` is not implemented for `A`
note: required because it appears within the type `Bar<A>`
Expand Down Expand Up @@ -73,10 +73,10 @@ LL | struct Bar<T: ?Sized> {
| ^ required by this bound in `Bar`

error[E0277]: the size for values of type `A` cannot be known at compilation time
--> $DIR/extern-types-unsized.rs:32:20
--> $DIR/extern-types-unsized.rs:32:28
|
LL | assert_sized::<Bar<Bar<A>>>();
| ^^^^^^^^^^^ doesn't have a size known at compile-time
| ^ doesn't have a size known at compile-time
|
= help: within `Bar<Bar<A>>`, the trait `Sized` is not implemented for `A`
note: required because it appears within the type `Bar<A>`
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/extern/issue-36122-accessing-externed-dst.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `[usize]` cannot be known at compilation time
--> $DIR/issue-36122-accessing-externed-dst.rs:3:9
--> $DIR/issue-36122-accessing-externed-dst.rs:3:24
|
LL | static symbol: [usize];
| ^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `[usize]`
= note: statics and constants must have a statically known size
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/feature-gates/feature-gate-trivial_bounds.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -105,7 +105,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
--> $DIR/feature-gate-trivial_bounds.rs:52:32
|
LL | struct TwoStrs(str, str) where str: Sized;
| ^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= help: see issue #48214
Expand Down Expand Up @@ -136,7 +136,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
--> $DIR/feature-gate-trivial_bounds.rs:59:30
|
LL | fn return_str() -> str where str: Sized {
| ^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= help: see issue #48214
Expand Down
8 changes: 4 additions & 4 deletions tests/ui/function-pointer/unsized-ret.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `str` cannot be known at compilation time
--> $DIR/unsized-ret.rs:10:11
--> $DIR/unsized-ret.rs:10:19
|
LL | foo::<fn() -> str, _>(None, ());
| ^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: within `fn() -> str`, the trait `Sized` is not implemented for `str`
= note: required because it appears within the type `fn() -> str`
Expand All @@ -13,10 +13,10 @@ LL | fn foo<F: Fn<T>, T:std::marker::Tuple>(f: Option<F>, t: T) {
| ^^^^^ required by this bound in `foo`

error[E0277]: the size for values of type `(dyn std::fmt::Display + 'a)` cannot be known at compilation time
--> $DIR/unsized-ret.rs:13:11
--> $DIR/unsized-ret.rs:13:33
|
LL | foo::<for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a), _>(None, (&(),));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
|
= help: within `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a)`, the trait `for<'a> Sized` is not implemented for `(dyn std::fmt::Display + 'a)`
= note: required because it appears within the type `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a)`
Expand Down
4 changes: 2 additions & 2 deletions tests/ui/higher-ranked/well-formed-aliases.stderr
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
error[E0277]: the size for values of type `str` cannot be known at compilation time
--> $DIR/well-formed-aliases.rs:5:52
--> $DIR/well-formed-aliases.rs:5:53
|
LL | fn test<T>(f: for<'a> fn(<&'a T as Trait>::Gat<&'a [str]>)) where for<'a> &'a T: Trait {}
| ^^^^^ doesn't have a size known at compile-time
| ^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `str`
= note: slice and array elements must have `Sized` type
Expand Down
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