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Rollup merge of #125635 - fmease:mv-type-binding-assoc-item-constraint, r=compiler-errors

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Rename HIR `TypeBinding` to `AssocItemConstraint` and related cleanup

Rename `hir::TypeBinding` and `ast::AssocConstraint` to `AssocItemConstraint` and update all items and locals using the old terminology.

Motivation: The terminology *type binding* is extremely outdated. "Type bindings" not only include constraints on associated *types* but also on associated *constants* (feature `associated_const_equality`) and on RPITITs of associated *functions* (feature `return_type_notation`). Hence the word *item* in the new name. Furthermore, the word *binding* commonly refers to a mapping from a binder/identifier to a "value" for some definition of "value". Its use in "type binding" made sense when equality constraints (e.g., `AssocTy = Ty`) were the only kind of associated item constraint. Nowadays however, we also have *associated type bounds* (e.g., `AssocTy: Bound`) for which the term *binding* doesn't make sense.

---

Old terminology (HIR, rustdoc):

```
`TypeBinding`: (associated) type binding
├── `Constraint`: associated type bound
└── `Equality`: (associated) equality constraint (?)
    ├── `Ty`: (associated) type binding
    └── `Const`: associated const equality (constraint)
```

Old terminology (AST, abbrev.):

```
`AssocConstraint`
├── `Bound`
└── `Equality`
    ├── `Ty`
    └── `Const`
```

New terminology (AST, HIR, rustdoc):

```
`AssocItemConstraint`: associated item constraint
├── `Bound`: associated type bound
└── `Equality`: associated item equality constraint OR associated item binding (for short)
    ├── `Ty`: associated type equality constraint OR associated type binding (for short)
    └── `Const`: associated const equality constraint OR associated const binding (for short)
```

r? compiler-errors
This commit is contained in:
Matthias Krüger 2024-05-31 08:50:22 +02:00 • committed by GitHub
commit 379233242b
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GPG key ID: B5690EEEBB952194
108 changed files with 878 additions and 818 deletions
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8
compiler/rustc_ast_lowering/src/index.rs
View file

@ -325,10 +325,10 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
});
}
fn visit_assoc_type_binding(&mut self, type_binding: &'hir TypeBinding<'hir>) {
self.insert(type_binding.span, type_binding.hir_id, Node::TypeBinding(type_binding));
self.with_parent(type_binding.hir_id, |this| {
intravisit::walk_assoc_type_binding(this, type_binding)
fn visit_assoc_item_constraint(&mut self, constraint: &'hir AssocItemConstraint<'hir>) {
self.insert(constraint.span, constraint.hir_id, Node::AssocItemConstraint(constraint));
self.with_parent(constraint.hir_id, |this| {
intravisit::walk_assoc_item_constraint(this, constraint)
})
}

51
compiler/rustc_ast_lowering/src/lib.rs
View file

@ -967,24 +967,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
DelimArgs { dspan: args.dspan, delim: args.delim, tokens: args.tokens.flattened() }
}
/// Given an associated type constraint like one of these:
///
/// ```ignore (illustrative)
/// T: Iterator<Item: Debug>
/// ^^^^^^^^^^^
/// T: Iterator<Item = Debug>
/// ^^^^^^^^^^^^
/// ```
///
/// returns a `hir::TypeBinding` representing `Item`.
#[instrument(level = "debug", skip(self))]
fn lower_assoc_ty_constraint(
/// Lower an associated item constraint.
#[instrument(level = "debug", skip_all)]
fn lower_assoc_item_constraint(
&mut self,
constraint: &AssocConstraint,
constraint: &AssocItemConstraint,
itctx: ImplTraitContext,
) -> hir::TypeBinding<'hir> {
debug!("lower_assoc_ty_constraint(constraint={:?}, itctx={:?})", constraint, itctx);
// lower generic arguments of identifier in constraint
) -> hir::AssocItemConstraint<'hir> {
debug!(?constraint, ?itctx);
// Lower the generic arguments for the associated item.
let gen_args = if let Some(gen_args) = &constraint.gen_args {
let gen_args_ctor = match gen_args {
GenericArgs::AngleBracketed(data) => {
@ -1000,7 +991,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
};
GenericArgsCtor {
args: Default::default(),
bindings: &[],
constraints: &[],
parenthesized,
span: data.inputs_span,
}
@ -1030,7 +1021,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
err.emit();
GenericArgsCtor {
args: Default::default(),
bindings: &[],
constraints: &[],
parenthesized: hir::GenericArgsParentheses::ReturnTypeNotation,
span: data.span,
}
@ -1052,14 +1043,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
self.arena.alloc(hir::GenericArgs::none())
};
let kind = match &constraint.kind {
AssocConstraintKind::Equality { term } => {
AssocItemConstraintKind::Equality { term } => {
let term = match term {
Term::Ty(ty) => self.lower_ty(ty, itctx).into(),
Term::Const(c) => self.lower_anon_const(c).into(),
};
hir::TypeBindingKind::Equality { term }
hir::AssocItemConstraintKind::Equality { term }
}
AssocConstraintKind::Bound { bounds } => {
AssocItemConstraintKind::Bound { bounds } => {
// Disallow ATB in dyn types
if self.is_in_dyn_type {
let suggestion = match itctx {
@ -1083,18 +1074,18 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
});
let err_ty =
&*self.arena.alloc(self.ty(constraint.span, hir::TyKind::Err(guar)));
hir::TypeBindingKind::Equality { term: err_ty.into() }
hir::AssocItemConstraintKind::Equality { term: err_ty.into() }
} else {
// Desugar `AssocTy: Bounds` into a type binding where the
// Desugar `AssocTy: Bounds` into an assoc type binding where the
// later desugars into a trait predicate.
let bounds = self.lower_param_bounds(bounds, itctx);
hir::TypeBindingKind::Constraint { bounds }
hir::AssocItemConstraintKind::Bound { bounds }
}
}
};
hir::TypeBinding {
hir::AssocItemConstraint {
hir_id: self.lower_node_id(constraint.id),
ident: self.lower_ident(constraint.ident),
gen_args,
@ -2014,7 +2005,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
let bound_args = self.arena.alloc(hir::GenericArgs {
args: &[],
bindings: arena_vec![self; self.assoc_ty_binding(assoc_ty_name, opaque_ty_span, output_ty)],
constraints: arena_vec![self; self.assoc_ty_binding(assoc_ty_name, opaque_ty_span, output_ty)],
parenthesized: hir::GenericArgsParentheses::No,
span_ext: DUMMY_SP,
});
@ -2587,10 +2578,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
}
}
/// Helper struct for delayed construction of GenericArgs.
/// Helper struct for the delayed construction of [`hir::GenericArgs`].
struct GenericArgsCtor<'hir> {
args: SmallVec<[hir::GenericArg<'hir>; 4]>,
bindings: &'hir [hir::TypeBinding<'hir>],
constraints: &'hir [hir::AssocItemConstraint<'hir>],
parenthesized: hir::GenericArgsParentheses,
span: Span,
}
@ -2670,14 +2661,14 @@ impl<'hir> GenericArgsCtor<'hir> {
fn is_empty(&self) -> bool {
self.args.is_empty()
&& self.bindings.is_empty()
&& self.constraints.is_empty()
&& self.parenthesized == hir::GenericArgsParentheses::No
}
fn into_generic_args(self, this: &LoweringContext<'_, 'hir>) -> &'hir hir::GenericArgs<'hir> {
let ga = hir::GenericArgs {
args: this.arena.alloc_from_iter(self.args),
bindings: self.bindings,
constraints: self.constraints,
parenthesized: self.parenthesized,
span_ext: this.lower_span(self.span),
};

31
compiler/rustc_ast_lowering/src/path.rs
View file

@ -281,7 +281,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
(
GenericArgsCtor {
args: Default::default(),
bindings: &[],
constraints: &[],
parenthesized: hir::GenericArgsParentheses::No,
span: path_span.shrink_to_hi(),
},
@ -390,13 +390,16 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
AngleBracketedArg::Constraint(_) => None,
})
.collect();
let bindings = self.arena.alloc_from_iter(data.args.iter().filter_map(|arg| match arg {
AngleBracketedArg::Constraint(c) => Some(self.lower_assoc_ty_constraint(c, itctx)),
AngleBracketedArg::Arg(_) => None,
}));
let constraints =
self.arena.alloc_from_iter(data.args.iter().filter_map(|arg| match arg {
AngleBracketedArg::Constraint(c) => {
Some(self.lower_assoc_item_constraint(c, itctx))
}
AngleBracketedArg::Arg(_) => None,
}));
let ctor = GenericArgsCtor {
args,
bindings,
constraints,
parenthesized: hir::GenericArgsParentheses::No,
span: data.span,
};
@ -454,12 +457,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
Some(bound_modifier_allowed_features),
);
}
let binding = self.assoc_ty_binding(sym::Output, output_span, output_ty);
let constraint = self.assoc_ty_binding(sym::Output, output_span, output_ty);
(
GenericArgsCtor {
args,
bindings: arena_vec![self; binding],
constraints: arena_vec![self; constraint],
parenthesized: hir::GenericArgsParentheses::ParenSugar,
span: data.inputs_span,
},
@ -467,24 +470,24 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
)
}
/// An associated type binding `$assoc_ty_name = $ty`.
/// An associated type binding (i.e., associated type equality constraint).
pub(crate) fn assoc_ty_binding(
&mut self,
assoc_ty_name: rustc_span::Symbol,
span: Span,
ty: &'hir hir::Ty<'hir>,
) -> hir::TypeBinding<'hir> {
) -> hir::AssocItemConstraint<'hir> {
let ident = Ident::with_dummy_span(assoc_ty_name);
let kind = hir::TypeBindingKind::Equality { term: ty.into() };
let kind = hir::AssocItemConstraintKind::Equality { term: ty.into() };
let args = arena_vec![self;];
let bindings = arena_vec![self;];
let constraints = arena_vec![self;];
let gen_args = self.arena.alloc(hir::GenericArgs {
args,
bindings,
constraints,
parenthesized: hir::GenericArgsParentheses::No,
span_ext: DUMMY_SP,
});
hir::TypeBinding {
hir::AssocItemConstraint {
hir_id: self.next_id(),
gen_args,
span: self.lower_span(span),