bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Move hir::Item::ident into hir::ItemKind.

Browse source 
`hir::Item` has an `ident` field.

- It's always non-empty for these item kinds: `ExternCrate`, `Static`,
  `Const`, `Fn`, `Macro`, `Mod`, `TyAlias`, `Enum`, `Struct`, `Union`,
  Trait`, TraitAalis`.

- It's always empty for these item kinds: `ForeignMod`, `GlobalAsm`,
  `Impl`.

- For `Use`, it is non-empty for `UseKind::Single` and empty for
  `UseKind::{Glob,ListStem}`.

All of this is quite non-obvious; the only documentation is a single
comment saying "The name might be a dummy name in case of anonymous
items". Some sites that handle items check for an empty ident, some
don't. This is a very C-like way of doing things, but this is Rust, we
have sum types, we can do this properly and never forget to check for
the exceptional case and never YOLO possibly empty identifiers (or
possibly dummy spans) around and hope that things will work out.

The commit is large but it's mostly obvious plumbing work. Some notable
things.

- A similar transformation makes sense for `ast::Item`, but this is
  already a big change. That can be done later.

- Lots of assertions are added to item lowering to ensure that
  identifiers are empty/non-empty as expected. These will be removable
  when `ast::Item` is done later.

- `ItemKind::Use` doesn't get an `Ident`, but `UseKind::Single` does.

- `lower_use_tree` is significantly simpler. No more confusing `&mut
  Ident` to deal with.

- `ItemKind::ident` is a new method, it returns an `Option<Ident>`. It's
  used with `unwrap` in a few places; sometimes it's hard to tell
  exactly which item kinds might occur. None of these unwraps fail on
  the test suite. It's conceivable that some might fail on alternative
  input. We can deal with those if/when they happen.

- In `trait_path` the `find_map`/`if let` is replaced with a loop, and
  things end up much clearer that way.

- `named_span` no longer checks for an empty name; instead the call site
  now checks for a missing identifier if necessary.

- `maybe_inline_local` doesn't need the `glob` argument, it can be
  computed in-function from the `renamed` argument.

- `arbitrary_source_item_ordering::check_mod` had a big `if` statement
  that was just getting the ident from the item kinds that had one. It
  could be mostly replaced by a single call to the new `ItemKind::ident`
  method.

- `ItemKind` grows from 56 to 64 bytes, but `Item` stays the same size,
  and that's what matters, because `ItemKind` only occurs within `Item`.
This commit is contained in:
Nicholas Nethercote 2025-03-06 19:07:36 +11:00
parent 6698c26b3a
commit f2ddbcd24b
82 changed files with 666 additions and 555 deletions
Download patch file Download diff file Expand all files Collapse all files

24
compiler/rustc_hir_analysis/src/check/wfcheck.rs
View file

@ -269,26 +269,26 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
}
res
}
hir::ItemKind::Fn { sig, .. } => {
check_item_fn(tcx, def_id, item.ident, item.span, sig.decl)
hir::ItemKind::Fn { ident, sig, .. } => {
check_item_fn(tcx, def_id, ident, item.span, sig.decl)
}
hir::ItemKind::Static(ty, ..) => {
hir::ItemKind::Static(_, ty, ..) => {
check_item_type(tcx, def_id, ty.span, UnsizedHandling::Forbid)
}
hir::ItemKind::Const(ty, ..) => {
hir::ItemKind::Const(_, ty, ..) => {
check_item_type(tcx, def_id, ty.span, UnsizedHandling::Forbid)
}
hir::ItemKind::Struct(_, hir_generics) => {
hir::ItemKind::Struct(_, _, hir_generics) => {
let res = check_type_defn(tcx, item, false);
check_variances_for_type_defn(tcx, item, hir_generics);
res
}
hir::ItemKind::Union(_, hir_generics) => {
hir::ItemKind::Union(_, _, hir_generics) => {
let res = check_type_defn(tcx, item, true);
check_variances_for_type_defn(tcx, item, hir_generics);
res
}
hir::ItemKind::Enum(_, hir_generics) => {
hir::ItemKind::Enum(_, _, hir_generics) => {
let res = check_type_defn(tcx, item, true);
check_variances_for_type_defn(tcx, item, hir_generics);
res
@ -297,7 +297,9 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
hir::ItemKind::TraitAlias(..) => check_trait(tcx, item),
// `ForeignItem`s are handled separately.
hir::ItemKind::ForeignMod { .. } => Ok(()),
hir::ItemKind::TyAlias(hir_ty, hir_generics) if tcx.type_alias_is_lazy(item.owner_id) => {
hir::ItemKind::TyAlias(_, hir_ty, hir_generics)
if tcx.type_alias_is_lazy(item.owner_id) =>
{
let res = enter_wf_checking_ctxt(tcx, item.span, def_id, |wfcx| {
let ty = tcx.type_of(def_id).instantiate_identity();
let item_ty = wfcx.normalize(hir_ty.span, Some(WellFormedLoc::Ty(def_id)), ty);
@ -822,10 +824,10 @@ fn could_be_self(trait_def_id: LocalDefId, ty: &hir::Ty<'_>) -> bool {
///
/// In such cases, suggest using `Self` instead.
fn check_dyn_incompatible_self_trait_by_name(tcx: TyCtxt<'_>, item: &hir::TraitItem<'_>) {
let (trait_name, trait_def_id) =
let (trait_ident, trait_def_id) =
match tcx.hir_node_by_def_id(tcx.hir_get_parent_item(item.hir_id()).def_id) {
hir::Node::Item(item) => match item.kind {
hir::ItemKind::Trait(..) => (item.ident, item.owner_id),
hir::ItemKind::Trait(_, _, ident, ..) => (ident, item.owner_id),
_ => return,
},
_ => return,
@ -862,7 +864,7 @@ fn check_dyn_incompatible_self_trait_by_name(tcx: TyCtxt<'_>, item: &hir::TraitI
trait_should_be_self,
"associated item referring to unboxed trait object for its own trait",
)
.with_span_label(trait_name.span, "in this trait")
.with_span_label(trait_ident.span, "in this trait")
.with_multipart_suggestion(
"you might have meant to use `Self` to refer to the implementing type",
sugg,

34
compiler/rustc_hir_analysis/src/collect.rs
View file

@ -247,13 +247,13 @@ fn reject_placeholder_type_signatures_in_item<'tcx>(
item: &'tcx hir::Item<'tcx>,
) {
let (generics, suggest) = match &item.kind {
hir::ItemKind::Union(_, generics)
| hir::ItemKind::Enum(_, generics)
| hir::ItemKind::TraitAlias(generics, _)
| hir::ItemKind::Trait(_, _, generics, ..)
hir::ItemKind::Union(_, _, generics)
| hir::ItemKind::Enum(_, _, generics)
| hir::ItemKind::TraitAlias(_, generics, _)
| hir::ItemKind::Trait(_, _, _, generics, ..)
| hir::ItemKind::Impl(hir::Impl { generics, .. })
| hir::ItemKind::Struct(_, generics) => (generics, true),
hir::ItemKind::TyAlias(_, generics) => (generics, false),
| hir::ItemKind::Struct(_, _, generics) => (generics, true),
hir::ItemKind::TyAlias(_, _, generics) => (generics, false),
// `static`, `fn` and `const` are handled elsewhere to suggest appropriate type.
_ => return,
};
@ -470,9 +470,9 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> {
.tcx
.hir_expect_item(self.tcx.hir_get_parent_item(self.hir_id()).def_id);
match &item.kind {
hir::ItemKind::Enum(_, generics)
| hir::ItemKind::Struct(_, generics)
| hir::ItemKind::Union(_, generics) => {
hir::ItemKind::Enum(_, _, generics)
| hir::ItemKind::Struct(_, _, generics)
| hir::ItemKind::Union(_, _, generics) => {
let lt_name = get_new_lifetime_name(self.tcx, poly_trait_ref, generics);
let (lt_sp, sugg) = match generics.params {
[] => (generics.span, format!("<{lt_name}>")),
@ -667,16 +667,16 @@ fn get_new_lifetime_name<'tcx>(
#[instrument(level = "debug", skip_all)]
fn lower_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
let it = tcx.hir_item(item_id);
debug!(item = %it.ident, id = %it.hir_id());
debug!(item = ?it.kind.ident(), id = %it.hir_id());
let def_id = item_id.owner_id.def_id;
let icx = ItemCtxt::new(tcx, def_id);
match &it.kind {
// These don't define types.
hir::ItemKind::ExternCrate(_)
hir::ItemKind::ExternCrate(..)
| hir::ItemKind::Use(..)
| hir::ItemKind::Macro(..)
| hir::ItemKind::Mod(_)
| hir::ItemKind::Mod(..)
| hir::ItemKind::GlobalAsm { .. } => {}
hir::ItemKind::ForeignMod { items, .. } => {
for item in *items {
@ -736,7 +736,7 @@ fn lower_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
tcx.at(it.span).explicit_super_predicates_of(def_id);
tcx.ensure_ok().predicates_of(def_id);
}
hir::ItemKind::Struct(struct_def, _) | hir::ItemKind::Union(struct_def, _) => {
hir::ItemKind::Struct(_, struct_def, _) | hir::ItemKind::Union(_, struct_def, _) => {
tcx.ensure_ok().generics_of(def_id);
tcx.ensure_ok().type_of(def_id);
tcx.ensure_ok().predicates_of(def_id);
@ -758,7 +758,7 @@ fn lower_item(tcx: TyCtxt<'_>, item_id: hir::ItemId) {
tcx.ensure_ok().predicates_of(def_id);
}
hir::ItemKind::Static(ty, ..) | hir::ItemKind::Const(ty, ..) => {
hir::ItemKind::Static(_, ty, ..) | hir::ItemKind::Const(_, ty, ..) => {
tcx.ensure_ok().generics_of(def_id);
tcx.ensure_ok().type_of(def_id);
tcx.ensure_ok().predicates_of(def_id);
@ -1089,7 +1089,7 @@ fn adt_def(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::AdtDef<'_> {
let repr = tcx.repr_options_of_def(def_id);
let (kind, variants) = match &item.kind {
ItemKind::Enum(def, _) => {
ItemKind::Enum(_, def, _) => {
let mut distance_from_explicit = 0;
let variants = def
.variants
@ -1117,7 +1117,7 @@ fn adt_def(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::AdtDef<'_> {
(AdtKind::Enum, variants)
}
ItemKind::Struct(def, _) | ItemKind::Union(def, _) => {
ItemKind::Struct(ident, def, _) | ItemKind::Union(ident, def, _) => {
let adt_kind = match item.kind {
ItemKind::Struct(..) => AdtKind::Struct,
_ => AdtKind::Union,
@ -1125,7 +1125,7 @@ fn adt_def(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::AdtDef<'_> {
let variants = std::iter::once(lower_variant(
tcx,
None,
item.ident,
*ident,
ty::VariantDiscr::Relative(0),
def,
adt_kind,

2
compiler/rustc_hir_analysis/src/collect/dump.rs
View file

@ -134,7 +134,7 @@ pub(crate) fn vtables<'tcx>(tcx: TyCtxt<'tcx>) {
};
tcx.vtable_entries(trait_ref)
}
hir::ItemKind::TyAlias(_, _) => {
hir::ItemKind::TyAlias(..) => {
let ty = tcx.type_of(def_id).instantiate_identity();
if ty.has_non_region_param() {
tcx.dcx().span_err(

7
compiler/rustc_hir_analysis/src/collect/predicates_of.rs
View file

@ -163,7 +163,8 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
}
}
ItemKind::Trait(_, _, _, self_bounds, ..) | ItemKind::TraitAlias(_, self_bounds) => {
ItemKind::Trait(_, _, _, _, self_bounds, ..)
| ItemKind::TraitAlias(_, _, self_bounds) => {
is_trait = Some(self_bounds);
}
_ => {}
@ -615,7 +616,7 @@ pub(super) fn implied_predicates_with_filter<'tcx>(
let (generics, superbounds) = match item.kind {
hir::ItemKind::Trait(.., generics, supertraits, _) => (generics, supertraits),
hir::ItemKind::TraitAlias(generics, supertraits) => (generics, supertraits),
hir::ItemKind::TraitAlias(_, generics, supertraits) => (generics, supertraits),
_ => span_bug!(item.span, "super_predicates invoked on non-trait"),
};
@ -959,7 +960,7 @@ pub(super) fn const_conditions<'tcx>(
Node::Item(item) => match item.kind {
hir::ItemKind::Impl(impl_) => (impl_.generics, None, false),
hir::ItemKind::Fn { generics, .. } => (generics, None, false),
hir::ItemKind::Trait(_, _, generics, supertraits, _) => {
hir::ItemKind::Trait(_, _, _, generics, supertraits, _) => {
(generics, Some((item.owner_id.def_id, supertraits)), false)
}
_ => bug!("const_conditions called on wrong item: {def_id:?}"),

16
compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
View file

@ -617,7 +617,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
});
}
hir::ItemKind::ExternCrate(_)
hir::ItemKind::ExternCrate(..)
| hir::ItemKind::Use(..)
| hir::ItemKind::Macro(..)
| hir::ItemKind::Mod(..)
@ -627,13 +627,13 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
// These sorts of items have no lifetime parameters at all.
intravisit::walk_item(self, item);
}
hir::ItemKind::TyAlias(_, generics)
| hir::ItemKind::Const(_, generics, _)
| hir::ItemKind::Enum(_, generics)
| hir::ItemKind::Struct(_, generics)
| hir::ItemKind::Union(_, generics)
| hir::ItemKind::Trait(_, _, generics, ..)
| hir::ItemKind::TraitAlias(generics, ..)
hir::ItemKind::TyAlias(_, _, generics)
| hir::ItemKind::Const(_, _, generics, _)
| hir::ItemKind::Enum(_, _, generics)
| hir::ItemKind::Struct(_, _, generics)
| hir::ItemKind::Union(_, _, generics)
| hir::ItemKind::Trait(_, _, _, generics, ..)
| hir::ItemKind::TraitAlias(_, generics, ..)
| hir::ItemKind::Impl(&hir::Impl { generics, .. }) => {
// These kinds of items have only early-bound lifetime parameters.
self.visit_early(item.hir_id(), generics, |this| intravisit::walk_item(this, item));

12
compiler/rustc_hir_analysis/src/collect/type_of.rs
View file

@ -202,35 +202,35 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_
},
Node::Item(item) => match item.kind {
ItemKind::Static(ty, .., body_id) => {
ItemKind::Static(ident, ty, .., body_id) => {
if ty.is_suggestable_infer_ty() {
infer_placeholder_type(
icx.lowerer(),
def_id,
body_id,
ty.span,
item.ident,
ident,
"static variable",
)
} else {
icx.lower_ty(ty)
}
}
ItemKind::Const(ty, _, body_id) => {
ItemKind::Const(ident, ty, _, body_id) => {
if ty.is_suggestable_infer_ty() {
infer_placeholder_type(
icx.lowerer(),
def_id,
body_id,
ty.span,
item.ident,
ident,
"constant",
)
} else {
icx.lower_ty(ty)
}
}
ItemKind::TyAlias(self_ty, _) => icx.lower_ty(self_ty),
ItemKind::TyAlias(_, self_ty, _) => icx.lower_ty(self_ty),
ItemKind::Impl(hir::Impl { self_ty, .. }) => match self_ty.find_self_aliases() {
spans if spans.len() > 0 => {
let guar = tcx
@ -479,5 +479,5 @@ pub(crate) fn type_alias_is_lazy<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) ->
}
}
}
HasTait.visit_ty_unambig(tcx.hir_expect_item(def_id).expect_ty_alias().0).is_break()
HasTait.visit_ty_unambig(tcx.hir_expect_item(def_id).expect_ty_alias().1).is_break()
}

7
compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
View file

@ -140,14 +140,15 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
let generics = match tcx.hir_node_by_def_id(parent_item) {
hir::Node::Item(hir::Item {
kind: hir::ItemKind::Struct(variant, generics), ..
kind: hir::ItemKind::Struct(_, variant, generics),
..
}) => {
if !variant.fields().iter().any(|field| field.hir_id == parent_hir_id) {
return false;
}
generics
}
hir::Node::Item(hir::Item { kind: hir::ItemKind::Enum(def, generics), .. }) => {
hir::Node::Item(hir::Item { kind: hir::ItemKind::Enum(_, def, generics), .. }) => {
if !def
.variants
.iter()
@ -267,7 +268,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
hir::Node::Field(field) => {
// Enums can't have unsized fields, fields can only have an unsized tail field.
if let hir::Node::Item(hir::Item {
kind: hir::ItemKind::Struct(variant, _), ..
kind: hir::ItemKind::Struct(_, variant, _), ..
}) = tcx.parent_hir_node(field.hir_id)
&& variant
.fields()

6
compiler/rustc_hir_analysis/src/hir_wf_check.rs
View file

@ -136,9 +136,9 @@ fn diagnostic_hir_wf_check<'tcx>(
ref item => bug!("Unexpected TraitItem {:?}", item),
},
hir::Node::Item(item) => match item.kind {
hir::ItemKind::TyAlias(ty, _)
| hir::ItemKind::Static(ty, _, _)
| hir::ItemKind::Const(ty, _, _) => vec![ty],
hir::ItemKind::TyAlias(_, ty, _)
| hir::ItemKind::Static(_, ty, _, _)
| hir::ItemKind::Const(_, ty, _, _) => vec![ty],
hir::ItemKind::Impl(impl_) => match &impl_.of_trait {
Some(t) => t
.path