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BennoLossinBennoLossin
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add field traits
1 parent 03707aa commit 154f5cb

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9 files changed

+122
-6
lines changed

9 files changed

+122
-6
lines changed

‎compiler/rustc_hir/src/lang_items.rs‎

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Original file line numberDiff line numberDiff line change
@@ -440,6 +440,14 @@ language_item_table! {
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// Reborrowing related lang-items
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Reborrow, sym::reborrow, reborrow, Target::Trait, GenericRequirement::Exact(0);
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// Experimental lang items for field projections.
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Field, sym::Field, field_trait, Target::Trait, GenericRequirement::None;
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UnalignedField, sym::UnalignedField, unaligned_field_trait, Target::Trait, GenericRequirement::None;
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UnalignedFieldBase, sym::UnalignedFieldBase, unaligned_field_base, Target::AssocTy, GenericRequirement::None;
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UnalignedFieldType, sym::UnalignedFieldType, unaligned_field_type, Target::AssocTy, GenericRequirement::None;
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UnalignedFieldOFFSET, sym::UnalignedFieldOFFSET, unaligned_field_offset, Target::AssocConst, GenericRequirement::None;
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UnalignedFieldOffset, sym::unaligned_field_offset, unaligned_field_offset_getter, Target::Fn, GenericRequirement::Exact(1);
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}
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/// The requirement imposed on the generics of a lang item

‎compiler/rustc_middle/src/ty/context.rs‎

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@@ -831,6 +831,7 @@ bidirectional_lang_item_map! {
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Destruct,
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DiscriminantKind,
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Drop,
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Field,
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Fn,
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FnMut,
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FnOnce,
@@ -844,6 +845,7 @@ bidirectional_lang_item_map! {
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Sized,
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TransmuteTrait,
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Tuple,
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UnalignedField,
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Unpin,
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Unsize,
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// tidy-alphabetical-end
@@ -2579,6 +2581,7 @@ impl<'tcx> TyCtxt<'tcx> {
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fmt,
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self,
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Adt,
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Field,
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Array,
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Slice,
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RawPtr,

‎compiler/rustc_span/src/symbol.rs‎

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Original file line numberDiff line numberDiff line change
@@ -234,6 +234,7 @@ symbols! {
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Equal,
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Err,
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Error,
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Field,
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File,
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FileType,
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FmtArgumentsNew,
@@ -378,6 +379,10 @@ symbols! {
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Ty,
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TyCtxt,
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TyKind,
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UnalignedField,
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UnalignedFieldBase,
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UnalignedFieldOFFSET,
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UnalignedFieldType,
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Unknown,
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Unsize,
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UnsizedConstParamTy,

‎compiler/rustc_trait_selection/src/traits/project.rs‎

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Original file line numberDiff line numberDiff line change
@@ -996,7 +996,9 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
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| LangItem::FnOnce
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| LangItem::AsyncFn
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| LangItem::AsyncFnMut
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| LangItem::AsyncFnOnce,
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| LangItem::AsyncFnOnce
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| LangItem::Field
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| LangItem::UnalignedField,
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) => true,
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Some(LangItem::AsyncFnKindHelper) => {
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// FIXME(async_closures): Validity constraints here could be cleaned up.

‎compiler/rustc_trait_selection/src/traits/select/confirmation.rs‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -282,7 +282,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
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| LangItem::FnPtrTrait
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| LangItem::PointeeTrait
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| LangItem::Tuple
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| LangItem::Unpin,
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| LangItem::Unpin
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| LangItem::Field
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| LangItem::UnalignedField,
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) => ty::Binder::dummy(vec![]),
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other => bug!("unexpected builtin trait {trait_def:?} ({other:?})"),
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};

‎compiler/rustc_type_ir/src/lang_items.rs‎

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@@ -36,6 +36,7 @@ pub enum SolverTraitLangItem {
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Destruct,
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DiscriminantKind,
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Drop,
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Field,
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Fn,
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FnMut,
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FnOnce,
@@ -49,6 +50,7 @@ pub enum SolverTraitLangItem {
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Sized,
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TransmuteTrait,
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Tuple,
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UnalignedField,
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Unpin,
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Unsize,
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// tidy-alphabetical-end

‎library/core/src/field.rs‎

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Original file line numberDiff line numberDiff line change
@@ -1 +1,33 @@
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//! Field Reflection
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/// Type representing a field of a `struct`.
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///
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/// # Safety
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///
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/// Given a valid value of type `Self::Base`, there exists a valid value of type `Self::Type` at
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/// byte offset `OFFSET`.
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#[lang = "UnalignedField"]
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#[unstable(feature = "field_projections", issue = "145383")]
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pub unsafe trait UnalignedField: Sized {
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/// The type of the base where this field exists in.
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#[lang = "UnalignedFieldBase"]
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type Base: ?Sized;
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/// The type of the field.
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#[lang = "UnalignedFieldType"]
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type Type: ?Sized;
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/// The offset of the field in bytes.
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#[lang = "UnalignedFieldOFFSET"]
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const OFFSET: usize;
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}
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/// Type representing an aligned field of a `struct`.
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///
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/// # Safety
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///
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/// Given a well-aligned value of type `Self::Base`, the field at `Self::OFFSET` of type
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/// `Self::Type` is well-aligned.
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#[lang = "Field"]
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#[unstable(feature = "field_projections", issue = "145383")]
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pub unsafe trait Field: UnalignedField {}

‎tests/ui/feature-gates/feature-gate-field-projections.rs‎

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Original file line numberDiff line numberDiff line change
@@ -1,5 +1,17 @@
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#![allow(dead_code)]
22

3-
use std::field; //~ ERROR: use of unstable library feature `field_projections`
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use std::field::Field; //~ ERROR: use of unstable library feature `field_projections` [E0658]
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use std::ptr;
5+
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fn project_ref<F: Field>(
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//~^ ERROR: use of unstable library feature `field_projections` [E0658]
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r: &F::Base, //~ ERROR: use of unstable library feature `field_projections` [E0658]
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) -> &F::Type
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//~^ ERROR: use of unstable library feature `field_projections` [E0658]
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where
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F::Type: Sized, //~ ERROR: use of unstable library feature `field_projections` [E0658]
13+
{
14+
unsafe { &*ptr::from_ref(r).byte_add(F::OFFSET).cast() } //~ ERROR: use of unstable library feature `field_projections` [E0658]
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}
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517
fn main() {}

‎tests/ui/feature-gates/feature-gate-field-projections.stderr‎

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Original file line numberDiff line numberDiff line change
@@ -1,13 +1,63 @@
11
error[E0658]: use of unstable library feature `field_projections`
22
--> $DIR/feature-gate-field-projections.rs:3:5
33
|
4-
LL | use std::field;
5-
| ^^^^^^^^^^
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LL | use std::field::Field;
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| ^^^^^^^^^^^^^^^^^
66
|
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= note: see issue #145383 <https://github.com/rust-lang/rust/issues/145383> for more information
88
= help: add `#![feature(field_projections)]` to the crate attributes to enable
99
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
1010

11-
error: aborting due to 1 previous error
11+
error[E0658]: use of unstable library feature `field_projections`
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--> $DIR/feature-gate-field-projections.rs:6:19
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|
14+
LL | fn project_ref<F: Field>(
15+
| ^^^^^
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|
17+
= note: see issue #145383 <https://github.com/rust-lang/rust/issues/145383> for more information
18+
= help: add `#![feature(field_projections)]` to the crate attributes to enable
19+
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
20+
21+
error[E0658]: use of unstable library feature `field_projections`
22+
--> $DIR/feature-gate-field-projections.rs:12:5
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|
24+
LL | F::Type: Sized,
25+
| ^^^^^^^
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|
27+
= note: see issue #145383 <https://github.com/rust-lang/rust/issues/145383> for more information
28+
= help: add `#![feature(field_projections)]` to the crate attributes to enable
29+
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
30+
31+
error[E0658]: use of unstable library feature `field_projections`
32+
--> $DIR/feature-gate-field-projections.rs:8:9
33+
|
34+
LL | r: &F::Base,
35+
| ^^^^^^^
36+
|
37+
= note: see issue #145383 <https://github.com/rust-lang/rust/issues/145383> for more information
38+
= help: add `#![feature(field_projections)]` to the crate attributes to enable
39+
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
40+
41+
error[E0658]: use of unstable library feature `field_projections`
42+
--> $DIR/feature-gate-field-projections.rs:9:7
43+
|
44+
LL | ) -> &F::Type
45+
| ^^^^^^^
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|
47+
= note: see issue #145383 <https://github.com/rust-lang/rust/issues/145383> for more information
48+
= help: add `#![feature(field_projections)]` to the crate attributes to enable
49+
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
50+
51+
error[E0658]: use of unstable library feature `field_projections`
52+
--> $DIR/feature-gate-field-projections.rs:14:42
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|
54+
LL | unsafe { &*ptr::from_ref(r).byte_add(F::OFFSET).cast() }
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| ^^^^^^^^^
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|
57+
= note: see issue #145383 <https://github.com/rust-lang/rust/issues/145383> for more information
58+
= help: add `#![feature(field_projections)]` to the crate attributes to enable
59+
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
60+
61+
error: aborting due to 6 previous errors
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1363
For more information about this error, try `rustc --explain E0658`.

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