use rustc_data_structures::fx::FxIndexMap;
use rustc_hir as hir;
-use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def::{CtorOf, DefKind, Res};
use rustc_hir::def_id::LocalDefId;
+use rustc_hir::pat_util::EnumerateAndAdjustIterator;
use rustc_hir::PatKind;
+use rustc_index::vec::Idx;
use rustc_infer::infer::InferCtxt;
use rustc_span::Span;
+use rustc_target::abi::VariantIdx;
use rustc_trait_selection::infer::InferCtxtExt;
#[derive(Clone, Debug)]
pub enum ProjectionKind {
/// A dereference of a pointer, reference or `Box<T>` of the given type
Deref,
- /// An index or a field
- Other,
+
+ /// `B.F` where `B` is the base expression and `F` is
+ /// the field. The field is identified by which variant
+ /// it appears in along with a field index. The variant
+ /// is used for enums.
+ Field(u32, VariantIdx),
+
+ /// Some index like `B[x]`, where `B` is the base
+ /// expression. We don't preserve the index `x` because
+ /// we won't need it.
+ Index,
+
+ /// A subslice covering a range of values like `B[x..y]`.
+ Subslice,
}
#[derive(Clone, Debug)]
hir::ExprKind::Field(ref base, _) => {
let base = self.cat_expr(&base)?;
debug!("cat_expr(cat_field): id={} expr={:?} base={:?}", expr.hir_id, expr, base);
- Ok(self.cat_projection(expr, base, expr_ty))
+
+ let field_idx = self
+ .tables
+ .field_indices()
+ .get(expr.hir_id)
+ .cloned()
+ .expect("Field index not found");
+
+ Ok(self.cat_projection(
+ expr,
+ base,
+ expr_ty,
+ ProjectionKind::Field(field_idx as u32, VariantIdx::new(0)),
+ ))
}
hir::ExprKind::Index(ref base, _) => {
self.cat_overloaded_place(expr, base)
} else {
let base = self.cat_expr(&base)?;
- Ok(self.cat_projection(expr, base, expr_ty))
+ Ok(self.cat_projection(expr, base, expr_ty, ProjectionKind::Index))
}
}
node: &N,
base_place: PlaceWithHirId<'tcx>,
ty: Ty<'tcx>,
+ kind: ProjectionKind,
) -> PlaceWithHirId<'tcx> {
let mut projections = base_place.place.projections;
- projections.push(Projection { kind: ProjectionKind::Other, ty: ty });
+ projections.push(Projection { kind: kind, ty: ty });
let ret = PlaceWithHirId::new(
node.hir_id(),
base_place.place.base_ty,
self.cat_pattern_(place, pat, &mut op)
}
+ /// Returns the variant index for an ADT used within a Struct or TupleStruct pattern
+ /// Here `pat_hir_id` is the HirId of the pattern itself.
+ fn variant_index_for_adt(
+ &self,
+ qpath: &hir::QPath<'_>,
+ pat_hir_id: hir::HirId,
+ span: Span,
+ ) -> McResult<VariantIdx> {
+ let res = self.tables.qpath_res(qpath, pat_hir_id);
+ let ty = self.tables.node_type(pat_hir_id);
+ let adt_def = match ty.kind {
+ ty::Adt(adt_def, _) => adt_def,
+ _ => {
+ self.tcx()
+ .sess
+ .delay_span_bug(span, "struct or tuple struct pattern not applied to an ADT");
+ return Err(());
+ }
+ };
+
+ match res {
+ Res::Def(DefKind::Variant, variant_id) => Ok(adt_def.variant_index_with_id(variant_id)),
+ Res::Def(DefKind::Ctor(CtorOf::Variant, ..), variant_ctor_id) => {
+ Ok(adt_def.variant_index_with_ctor_id(variant_ctor_id))
+ }
+ Res::Def(DefKind::Ctor(CtorOf::Struct, ..), _)
+ | Res::Def(DefKind::Struct | DefKind::Union | DefKind::TyAlias | DefKind::AssocTy, _)
+ | Res::SelfCtor(..)
+ | Res::SelfTy(..) => {
+ // Structs and Unions have only have one variant.
+ Ok(VariantIdx::new(0))
+ }
+ _ => bug!("expected ADT path, found={:?}", res),
+ }
+ }
+
+ /// Returns the total number of fields in an ADT variant used within a pattern.
+ /// Here `pat_hir_id` is the HirId of the pattern itself.
+ fn total_fields_in_adt_variant(
+ &self,
+ pat_hir_id: hir::HirId,
+ variant_index: VariantIdx,
+ span: Span,
+ ) -> McResult<usize> {
+ let ty = self.tables.node_type(pat_hir_id);
+ match ty.kind {
+ ty::Adt(adt_def, _) => Ok(adt_def.variants[variant_index].fields.len()),
+ _ => {
+ self.tcx()
+ .sess
+ .delay_span_bug(span, "struct or tuple struct pattern not applied to an ADT");
+ return Err(());
+ }
+ }
+ }
+
+ /// Returns the total number of fields in a tuple used within a Tuple pattern.
+ /// Here `pat_hir_id` is the HirId of the pattern itself.
+ fn total_fields_in_tuple(&self, pat_hir_id: hir::HirId, span: Span) -> McResult<usize> {
+ let ty = self.tables.node_type(pat_hir_id);
+ match ty.kind {
+ ty::Tuple(substs) => Ok(substs.len()),
+ _ => {
+ self.tcx().sess.delay_span_bug(span, "tuple pattern not applied to a tuple");
+ return Err(());
+ }
+ }
+ }
+
// FIXME(#19596) This is a workaround, but there should be a better way to do this
fn cat_pattern_<F>(
&self,
op(&place_with_id, pat);
match pat.kind {
- PatKind::TupleStruct(_, ref subpats, _) | PatKind::Tuple(ref subpats, _) => {
- // S(p1, ..., pN) or (p1, ..., pN)
- for subpat in subpats.iter() {
+ PatKind::Tuple(ref subpats, dots_pos) => {
+ // (p1, ..., pN)
+ let total_fields = self.total_fields_in_tuple(pat.hir_id, pat.span)?;
+
+ for (i, subpat) in subpats.iter().enumerate_and_adjust(total_fields, dots_pos) {
let subpat_ty = self.pat_ty_adjusted(&subpat)?;
- let sub_place = self.cat_projection(pat, place_with_id.clone(), subpat_ty);
+ let projection_kind = ProjectionKind::Field(i as u32, VariantIdx::new(0));
+ let sub_place =
+ self.cat_projection(pat, place_with_id.clone(), subpat_ty, projection_kind);
self.cat_pattern_(sub_place, &subpat, op)?;
}
}
- PatKind::Struct(_, field_pats, _) => {
+ PatKind::TupleStruct(ref qpath, ref subpats, dots_pos) => {
+ // S(p1, ..., pN)
+ let variant_index = self.variant_index_for_adt(qpath, pat.hir_id, pat.span)?;
+ let total_fields =
+ self.total_fields_in_adt_variant(pat.hir_id, variant_index, pat.span)?;
+
+ for (i, subpat) in subpats.iter().enumerate_and_adjust(total_fields, dots_pos) {
+ let subpat_ty = self.pat_ty_adjusted(&subpat)?;
+ let projection_kind = ProjectionKind::Field(i as u32, variant_index);
+ let sub_place =
+ self.cat_projection(pat, place_with_id.clone(), subpat_ty, projection_kind);
+ self.cat_pattern_(sub_place, &subpat, op)?;
+ }
+ }
+
+ PatKind::Struct(ref qpath, field_pats, _) => {
// S { f1: p1, ..., fN: pN }
+
+ let variant_index = self.variant_index_for_adt(qpath, pat.hir_id, pat.span)?;
+
for fp in field_pats {
let field_ty = self.pat_ty_adjusted(&fp.pat)?;
- let field_place = self.cat_projection(pat, place_with_id.clone(), field_ty);
+ let field_index = self
+ .tables
+ .field_indices()
+ .get(fp.hir_id)
+ .cloned()
+ .expect("no index for a field");
+
+ let field_place = self.cat_projection(
+ pat,
+ place_with_id.clone(),
+ field_ty,
+ ProjectionKind::Field(field_index as u32, variant_index),
+ );
self.cat_pattern_(field_place, &fp.pat, op)?;
}
}
return Err(());
}
};
- let elt_place = self.cat_projection(pat, place_with_id.clone(), element_ty);
+ let elt_place = self.cat_projection(
+ pat,
+ place_with_id.clone(),
+ element_ty,
+ ProjectionKind::Index,
+ );
for before_pat in before {
self.cat_pattern_(elt_place.clone(), &before_pat, op)?;
}
if let Some(ref slice_pat) = *slice {
let slice_pat_ty = self.pat_ty_adjusted(&slice_pat)?;
- let slice_place = self.cat_projection(pat, place_with_id, slice_pat_ty);
+ let slice_place = self.cat_projection(
+ pat,
+ place_with_id,
+ slice_pat_ty,
+ ProjectionKind::Subslice,
+ );
self.cat_pattern_(slice_place, &slice_pat, op)?;
}
for after_pat in after {
projects / rust.git / commitdiff