diff options
Diffstat (limited to 'compiler/rustc_hir')
| -rw-r--r-- | compiler/rustc_hir/src/hir.rs | 66 | ||||
| -rw-r--r-- | compiler/rustc_hir/src/intravisit.rs | 26 |
2 files changed, 74 insertions, 18 deletions
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs index 3bd7b300758..bf773f2d487 100644 --- a/compiler/rustc_hir/src/hir.rs +++ b/compiler/rustc_hir/src/hir.rs @@ -228,13 +228,53 @@ impl<'hir> PathSegment<'hir> { } } +/// A constant that enters the type system, used for arguments to const generics (e.g. array lengths). +/// +/// These are distinct from [`AnonConst`] as anon consts in the type system are not allowed +/// to use any generic parameters, therefore we must represent `N` differently. Additionally +/// future designs for supporting generic parameters in const arguments will likely not use +/// an anon const based design. +/// +/// So, `ConstArg` (specifically, [`ConstArgKind`]) distinguishes between const args +/// that are [just paths](ConstArgKind::Path) (currently just bare const params) +/// versus const args that are literals or have arbitrary computations (e.g., `{ 1 + 3 }`). #[derive(Clone, Copy, Debug, HashStable_Generic)] pub struct ConstArg<'hir> { - pub value: &'hir AnonConst, + #[stable_hasher(ignore)] + pub hir_id: HirId, + pub kind: ConstArgKind<'hir>, /// Indicates whether this comes from a `~const` desugaring. pub is_desugared_from_effects: bool, } +impl<'hir> ConstArg<'hir> { + pub fn anon_const_hir_id(&self) -> Option<HirId> { + match self.kind { + ConstArgKind::Anon(ac) => Some(ac.hir_id), + _ => None, + } + } + + pub fn span(&self) -> Span { + match self.kind { + ConstArgKind::Path(path) => path.span(), + ConstArgKind::Anon(anon) => anon.span, + } + } +} + +/// See [`ConstArg`]. +#[derive(Clone, Copy, Debug, HashStable_Generic)] +pub enum ConstArgKind<'hir> { + /// **Note:** Currently this is only used for bare const params + /// (`N` where `fn foo<const N: usize>(...)`), + /// not paths to any const (`N` where `const N: usize = ...`). + /// + /// However, in the future, we'll be using it for all of those. + Path(QPath<'hir>), + Anon(&'hir AnonConst), +} + #[derive(Clone, Copy, Debug, HashStable_Generic)] pub struct InferArg { pub hir_id: HirId, @@ -251,7 +291,7 @@ impl InferArg { pub enum GenericArg<'hir> { Lifetime(&'hir Lifetime), Type(&'hir Ty<'hir>), - Const(ConstArg<'hir>), + Const(&'hir ConstArg<'hir>), Infer(InferArg), } @@ -260,7 +300,7 @@ impl GenericArg<'_> { match self { GenericArg::Lifetime(l) => l.ident.span, GenericArg::Type(t) => t.span, - GenericArg::Const(c) => c.value.span, + GenericArg::Const(c) => c.span(), GenericArg::Infer(i) => i.span, } } @@ -269,7 +309,7 @@ impl GenericArg<'_> { match self { GenericArg::Lifetime(l) => l.hir_id, GenericArg::Type(t) => t.hir_id, - GenericArg::Const(c) => c.value.hir_id, + GenericArg::Const(c) => c.hir_id, GenericArg::Infer(i) => i.hir_id, } } @@ -524,7 +564,7 @@ pub enum GenericParamKind<'hir> { Const { ty: &'hir Ty<'hir>, /// Optional default value for the const generic param - default: Option<&'hir AnonConst>, + default: Option<&'hir ConstArg<'hir>>, is_host_effect: bool, synthetic: bool, }, @@ -1598,13 +1638,13 @@ pub type Lit = Spanned<LitKind>; #[derive(Copy, Clone, Debug, HashStable_Generic)] pub enum ArrayLen<'hir> { Infer(InferArg), - Body(&'hir AnonConst), + Body(&'hir ConstArg<'hir>), } impl ArrayLen<'_> { pub fn hir_id(&self) -> HirId { match self { - ArrayLen::Infer(InferArg { hir_id, .. }) | ArrayLen::Body(AnonConst { hir_id, .. }) => { + ArrayLen::Infer(InferArg { hir_id, .. }) | ArrayLen::Body(ConstArg { hir_id, .. }) => { *hir_id } } @@ -2434,7 +2474,7 @@ impl<'hir> AssocItemConstraint<'hir> { } /// Obtain the const on the RHS of an assoc const equality constraint if applicable. - pub fn ct(self) -> Option<&'hir AnonConst> { + pub fn ct(self) -> Option<&'hir ConstArg<'hir>> { match self.kind { AssocItemConstraintKind::Equality { term: Term::Const(ct) } => Some(ct), _ => None, @@ -2445,7 +2485,7 @@ impl<'hir> AssocItemConstraint<'hir> { #[derive(Debug, Clone, Copy, HashStable_Generic)] pub enum Term<'hir> { Ty(&'hir Ty<'hir>), - Const(&'hir AnonConst), + Const(&'hir ConstArg<'hir>), } impl<'hir> From<&'hir Ty<'hir>> for Term<'hir> { @@ -2454,8 +2494,8 @@ impl<'hir> From<&'hir Ty<'hir>> for Term<'hir> { } } -impl<'hir> From<&'hir AnonConst> for Term<'hir> { - fn from(c: &'hir AnonConst) -> Self { +impl<'hir> From<&'hir ConstArg<'hir>> for Term<'hir> { + fn from(c: &'hir ConstArg<'hir>) -> Self { Term::Const(c) } } @@ -3689,6 +3729,7 @@ pub enum Node<'hir> { Field(&'hir FieldDef<'hir>), AnonConst(&'hir AnonConst), ConstBlock(&'hir ConstBlock), + ConstArg(&'hir ConstArg<'hir>), Expr(&'hir Expr<'hir>), ExprField(&'hir ExprField<'hir>), Stmt(&'hir Stmt<'hir>), @@ -3750,6 +3791,7 @@ impl<'hir> Node<'hir> { Node::Param(..) | Node::AnonConst(..) | Node::ConstBlock(..) + | Node::ConstArg(..) | Node::Expr(..) | Node::Stmt(..) | Node::Block(..) @@ -3966,7 +4008,7 @@ mod size_asserts { static_assert_size!(FnDecl<'_>, 40); static_assert_size!(ForeignItem<'_>, 72); static_assert_size!(ForeignItemKind<'_>, 40); - static_assert_size!(GenericArg<'_>, 24); + static_assert_size!(GenericArg<'_>, 16); static_assert_size!(GenericBound<'_>, 48); static_assert_size!(Generics<'_>, 56); static_assert_size!(Impl<'_>, 80); diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs index 9bb3245ae05..c202ee41e31 100644 --- a/compiler/rustc_hir/src/intravisit.rs +++ b/compiler/rustc_hir/src/intravisit.rs @@ -347,6 +347,9 @@ pub trait Visitor<'v>: Sized { fn visit_inline_const(&mut self, c: &'v ConstBlock) -> Self::Result { walk_inline_const(self, c) } + fn visit_const_arg(&mut self, c: &'v ConstArg<'v>) -> Self::Result { + walk_const_arg(self, c) + } fn visit_expr(&mut self, ex: &'v Expr<'v>) -> Self::Result { walk_expr(self, ex) } @@ -364,7 +367,7 @@ pub trait Visitor<'v>: Sized { fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) -> Self::Result { walk_generic_param(self, p) } - fn visit_const_param_default(&mut self, _param: HirId, ct: &'v AnonConst) -> Self::Result { + fn visit_const_param_default(&mut self, _param: HirId, ct: &'v ConstArg<'v>) -> Self::Result { walk_const_param_default(self, ct) } fn visit_generics(&mut self, g: &'v Generics<'v>) -> Self::Result { @@ -708,7 +711,7 @@ pub fn walk_array_len<'v, V: Visitor<'v>>(visitor: &mut V, len: &'v ArrayLen<'v> match len { // FIXME: Use `visit_infer` here. ArrayLen::Infer(InferArg { hir_id, span: _ }) => visitor.visit_id(*hir_id), - ArrayLen::Body(c) => visitor.visit_anon_const(c), + ArrayLen::Body(c) => visitor.visit_const_arg(c), } } @@ -725,6 +728,17 @@ pub fn walk_inline_const<'v, V: Visitor<'v>>( visitor.visit_nested_body(constant.body) } +pub fn walk_const_arg<'v, V: Visitor<'v>>( + visitor: &mut V, + const_arg: &'v ConstArg<'v>, +) -> V::Result { + try_visit!(visitor.visit_id(const_arg.hir_id)); + match &const_arg.kind { + ConstArgKind::Path(qpath) => visitor.visit_qpath(qpath, const_arg.hir_id, qpath.span()), + ConstArgKind::Anon(anon) => visitor.visit_anon_const(*anon), + } +} + pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) -> V::Result { try_visit!(visitor.visit_id(expression.hir_id)); match expression.kind { @@ -928,9 +942,9 @@ pub fn walk_generic_param<'v, V: Visitor<'v>>( pub fn walk_const_param_default<'v, V: Visitor<'v>>( visitor: &mut V, - ct: &'v AnonConst, + ct: &'v ConstArg<'v>, ) -> V::Result { - visitor.visit_anon_const(ct) + visitor.visit_const_arg(ct) } pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) -> V::Result { @@ -1216,7 +1230,7 @@ pub fn walk_generic_arg<'v, V: Visitor<'v>>( match generic_arg { GenericArg::Lifetime(lt) => visitor.visit_lifetime(lt), GenericArg::Type(ty) => visitor.visit_ty(ty), - GenericArg::Const(ct) => visitor.visit_anon_const(&ct.value), + GenericArg::Const(ct) => visitor.visit_const_arg(ct), GenericArg::Infer(inf) => visitor.visit_infer(inf), } } @@ -1278,7 +1292,7 @@ pub fn walk_assoc_item_constraint<'v, V: Visitor<'v>>( match constraint.kind { AssocItemConstraintKind::Equality { ref term } => match term { Term::Ty(ref ty) => try_visit!(visitor.visit_ty(ty)), - Term::Const(ref c) => try_visit!(visitor.visit_anon_const(c)), + Term::Const(ref c) => try_visit!(visitor.visit_const_arg(c)), }, AssocItemConstraintKind::Bound { bounds } => { walk_list!(visitor, visit_param_bound, bounds) |