Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/mir/lower.rs')
| -rw-r--r-- | crates/hir-ty/src/mir/lower.rs | 415 |
1 files changed, 29 insertions, 386 deletions
diff --git a/crates/hir-ty/src/mir/lower.rs b/crates/hir-ty/src/mir/lower.rs index d36d9e946c..4da0f87609 100644 --- a/crates/hir-ty/src/mir/lower.rs +++ b/crates/hir-ty/src/mir/lower.rs @@ -4,7 +4,7 @@ use std::{iter, mem, sync::Arc}; use chalk_ir::{BoundVar, ConstData, DebruijnIndex, TyKind}; use hir_def::{ - adt::VariantData, + adt::{VariantData, StructKind}, body::Body, expr::{ Array, BindingAnnotation, BindingId, ExprId, LabelId, Literal, MatchArm, Pat, PatId, @@ -28,6 +28,9 @@ use crate::{ use super::*; mod as_place; +mod pattern_matching; + +use pattern_matching::AdtPatternShape; #[derive(Debug, Clone, Copy)] struct LoopBlocks { @@ -107,12 +110,6 @@ impl MirLowerError { type Result<T> = std::result::Result<T, MirLowerError>; -enum AdtPatternShape<'a> { - Tuple { args: &'a [PatId], ellipsis: Option<usize> }, - Record { args: &'a [RecordFieldPat] }, - Unit, -} - impl MirLowerCtx<'_> { fn temp(&mut self, ty: Ty) -> Result<LocalId> { if matches!(ty.kind(Interner), TyKind::Slice(_) | TyKind::Dyn(_)) { @@ -275,15 +272,19 @@ impl MirLowerCtx<'_> { Ok(Some(current)) } ValueNs::EnumVariantId(variant_id) => { - let ty = self.infer.type_of_expr[expr_id].clone(); - let current = self.lower_enum_variant( - variant_id, - current, - place, - ty, - vec![], - expr_id.into(), - )?; + let variant_data = &self.db.enum_data(variant_id.parent).variants[variant_id.local_id]; + if variant_data.variant_data.kind() == StructKind::Unit { + let ty = self.infer.type_of_expr[expr_id].clone(); + current = self.lower_enum_variant( + variant_id, + current, + place, + ty, + vec![], + expr_id.into(), + )?; + } + // Otherwise its a tuple like enum, treated like a zero sized function, so no action is needed Ok(Some(current)) } ValueNs::GenericParam(p) => { @@ -517,10 +518,7 @@ impl MirLowerCtx<'_> { let cond_ty = self.expr_ty_after_adjustments(*expr); let mut end = None; for MatchArm { pat, guard, expr } in arms.iter() { - if guard.is_some() { - not_supported!("pattern matching with guard"); - } - let (then, otherwise) = self.pattern_match( + let (then, mut otherwise) = self.pattern_match( current, None, cond_place.clone(), @@ -528,6 +526,16 @@ impl MirLowerCtx<'_> { *pat, BindingAnnotation::Unannotated, )?; + let then = if let &Some(guard) = guard { + let next = self.new_basic_block(); + let o = otherwise.get_or_insert_with(|| self.new_basic_block()); + if let Some((discr, c)) = self.lower_expr_to_some_operand(guard, then)? { + self.set_terminator(c, Terminator::SwitchInt { discr, targets: SwitchTargets::static_if(1, next, *o) }); + } + next + } else { + then + }; if let Some(block) = self.lower_expr_to_place(*expr, place.clone(), then)? { let r = end.get_or_insert_with(|| self.new_basic_block()); self.set_goto(block, *r); @@ -922,7 +930,7 @@ impl MirLowerCtx<'_> { ) -> Result<BasicBlockId> { let subst = match ty.kind(Interner) { TyKind::Adt(_, subst) => subst.clone(), - _ => not_supported!("Non ADT enum"), + _ => implementation_error!("Non ADT enum"), }; self.push_assignment( prev_block, @@ -1020,355 +1028,6 @@ impl MirLowerCtx<'_> { self.push_statement(block, StatementKind::Assign(place, rvalue).with_span(span)); } - /// It gets a `current` unterminated block, appends some statements and possibly a terminator to it to check if - /// the pattern matches and write bindings, and returns two unterminated blocks, one for the matched path (which - /// can be the `current` block) and one for the mismatched path. If the input pattern is irrefutable, the - /// mismatched path block is `None`. - /// - /// By default, it will create a new block for mismatched path. If you already have one, you can provide it with - /// `current_else` argument to save an unneccessary jump. If `current_else` isn't `None`, the result mismatched path - /// wouldn't be `None` as well. Note that this function will add jumps to the beginning of the `current_else` block, - /// so it should be an empty block. - fn pattern_match( - &mut self, - mut current: BasicBlockId, - mut current_else: Option<BasicBlockId>, - mut cond_place: Place, - mut cond_ty: Ty, - pattern: PatId, - mut binding_mode: BindingAnnotation, - ) -> Result<(BasicBlockId, Option<BasicBlockId>)> { - Ok(match &self.body.pats[pattern] { - Pat::Missing => return Err(MirLowerError::IncompleteExpr), - Pat::Wild => (current, current_else), - Pat::Tuple { args, ellipsis } => { - pattern_matching_dereference(&mut cond_ty, &mut binding_mode, &mut cond_place); - let subst = match cond_ty.kind(Interner) { - TyKind::Tuple(_, s) => s, - _ => { - return Err(MirLowerError::TypeError( - "non tuple type matched with tuple pattern", - )) - } - }; - self.pattern_match_tuple_like( - current, - current_else, - args, - *ellipsis, - subst.iter(Interner).enumerate().map(|(i, x)| { - (PlaceElem::TupleField(i), x.assert_ty_ref(Interner).clone()) - }), - &cond_place, - binding_mode, - )? - } - Pat::Or(pats) => { - let then_target = self.new_basic_block(); - let mut finished = false; - for pat in &**pats { - let (next, next_else) = self.pattern_match( - current, - None, - cond_place.clone(), - cond_ty.clone(), - *pat, - binding_mode, - )?; - self.set_goto(next, then_target); - match next_else { - Some(t) => { - current = t; - } - None => { - finished = true; - break; - } - } - } - if !finished { - let ce = *current_else.get_or_insert_with(|| self.new_basic_block()); - self.set_goto(current, ce); - } - (then_target, current_else) - } - Pat::Record { args, .. } => { - let Some(variant) = self.infer.variant_resolution_for_pat(pattern) else { - not_supported!("unresolved variant"); - }; - self.pattern_matching_variant( - cond_ty, - binding_mode, - cond_place, - variant, - current, - pattern.into(), - current_else, - AdtPatternShape::Record { args: &*args }, - )? - } - Pat::Range { .. } => not_supported!("range pattern"), - Pat::Slice { .. } => not_supported!("slice pattern"), - Pat::Path(_) => { - let Some(variant) = self.infer.variant_resolution_for_pat(pattern) else { - not_supported!("unresolved variant"); - }; - self.pattern_matching_variant( - cond_ty, - binding_mode, - cond_place, - variant, - current, - pattern.into(), - current_else, - AdtPatternShape::Unit, - )? - } - Pat::Lit(l) => { - let then_target = self.new_basic_block(); - let else_target = current_else.unwrap_or_else(|| self.new_basic_block()); - match &self.body.exprs[*l] { - Expr::Literal(l) => match l { - hir_def::expr::Literal::Int(x, _) => { - self.set_terminator( - current, - Terminator::SwitchInt { - discr: Operand::Copy(cond_place), - targets: SwitchTargets::static_if( - *x as u128, - then_target, - else_target, - ), - }, - ); - } - hir_def::expr::Literal::Uint(x, _) => { - self.set_terminator( - current, - Terminator::SwitchInt { - discr: Operand::Copy(cond_place), - targets: SwitchTargets::static_if(*x, then_target, else_target), - }, - ); - } - _ => not_supported!("non int path literal"), - }, - _ => not_supported!("expression path literal"), - } - (then_target, Some(else_target)) - } - Pat::Bind { id, subpat } => { - let target_place = self.result.binding_locals[*id]; - let mode = self.body.bindings[*id].mode; - if let Some(subpat) = subpat { - (current, current_else) = self.pattern_match( - current, - current_else, - cond_place.clone(), - cond_ty, - *subpat, - binding_mode, - )? - } - if matches!(mode, BindingAnnotation::Ref | BindingAnnotation::RefMut) { - binding_mode = mode; - } - self.push_storage_live(*id, current); - self.push_assignment( - current, - target_place.into(), - match binding_mode { - BindingAnnotation::Unannotated | BindingAnnotation::Mutable => { - Operand::Copy(cond_place).into() - } - BindingAnnotation::Ref => Rvalue::Ref(BorrowKind::Shared, cond_place), - BindingAnnotation::RefMut => Rvalue::Ref( - BorrowKind::Mut { allow_two_phase_borrow: false }, - cond_place, - ), - }, - pattern.into(), - ); - (current, current_else) - } - Pat::TupleStruct { path: _, args, ellipsis } => { - let Some(variant) = self.infer.variant_resolution_for_pat(pattern) else { - not_supported!("unresolved variant"); - }; - self.pattern_matching_variant( - cond_ty, - binding_mode, - cond_place, - variant, - current, - pattern.into(), - current_else, - AdtPatternShape::Tuple { args, ellipsis: *ellipsis }, - )? - } - Pat::Ref { .. } => not_supported!("& pattern"), - Pat::Box { .. } => not_supported!("box pattern"), - Pat::ConstBlock(_) => not_supported!("const block pattern"), - }) - } - - fn pattern_matching_variant( - &mut self, - mut cond_ty: Ty, - mut binding_mode: BindingAnnotation, - mut cond_place: Place, - variant: VariantId, - current: BasicBlockId, - span: MirSpan, - current_else: Option<BasicBlockId>, - shape: AdtPatternShape<'_>, - ) -> Result<(BasicBlockId, Option<BasicBlockId>)> { - pattern_matching_dereference(&mut cond_ty, &mut binding_mode, &mut cond_place); - let subst = match cond_ty.kind(Interner) { - TyKind::Adt(_, s) => s, - _ => return Err(MirLowerError::TypeError("non adt type matched with tuple struct")), - }; - Ok(match variant { - VariantId::EnumVariantId(v) => { - let e = self.db.const_eval_discriminant(v)? as u128; - let next = self.new_basic_block(); - let tmp = self.discr_temp_place(); - self.push_assignment( - current, - tmp.clone(), - Rvalue::Discriminant(cond_place.clone()), - span, - ); - let else_target = current_else.unwrap_or_else(|| self.new_basic_block()); - self.set_terminator( - current, - Terminator::SwitchInt { - discr: Operand::Copy(tmp), - targets: SwitchTargets::static_if(e, next, else_target), - }, - ); - let enum_data = self.db.enum_data(v.parent); - self.pattern_matching_variant_fields( - shape, - &enum_data.variants[v.local_id].variant_data, - variant, - subst, - next, - Some(else_target), - &cond_place, - binding_mode, - )? - } - VariantId::StructId(s) => { - let struct_data = self.db.struct_data(s); - self.pattern_matching_variant_fields( - shape, - &struct_data.variant_data, - variant, - subst, - current, - current_else, - &cond_place, - binding_mode, - )? - } - VariantId::UnionId(_) => { - return Err(MirLowerError::TypeError("pattern matching on union")) - } - }) - } - - fn pattern_matching_variant_fields( - &mut self, - shape: AdtPatternShape<'_>, - variant_data: &VariantData, - v: VariantId, - subst: &Substitution, - current: BasicBlockId, - current_else: Option<BasicBlockId>, - cond_place: &Place, - binding_mode: BindingAnnotation, - ) -> Result<(BasicBlockId, Option<BasicBlockId>)> { - let fields_type = self.db.field_types(v); - Ok(match shape { - AdtPatternShape::Record { args } => { - let it = args - .iter() - .map(|x| { - let field_id = - variant_data.field(&x.name).ok_or(MirLowerError::UnresolvedField)?; - Ok(( - PlaceElem::Field(FieldId { parent: v.into(), local_id: field_id }), - x.pat, - fields_type[field_id].clone().substitute(Interner, subst), - )) - }) - .collect::<Result<Vec<_>>>()?; - self.pattern_match_adt( - current, - current_else, - it.into_iter(), - cond_place, - binding_mode, - )? - } - AdtPatternShape::Tuple { args, ellipsis } => { - let fields = variant_data.fields().iter().map(|(x, _)| { - ( - PlaceElem::Field(FieldId { parent: v.into(), local_id: x }), - fields_type[x].clone().substitute(Interner, subst), - ) - }); - self.pattern_match_tuple_like( - current, - current_else, - args, - ellipsis, - fields, - cond_place, - binding_mode, - )? - } - AdtPatternShape::Unit => (current, current_else), - }) - } - - fn pattern_match_adt( - &mut self, - mut current: BasicBlockId, - mut current_else: Option<BasicBlockId>, - args: impl Iterator<Item = (PlaceElem, PatId, Ty)>, - cond_place: &Place, - binding_mode: BindingAnnotation, - ) -> Result<(BasicBlockId, Option<BasicBlockId>)> { - for (proj, arg, ty) in args { - let mut cond_place = cond_place.clone(); - cond_place.projection.push(proj); - (current, current_else) = - self.pattern_match(current, current_else, cond_place, ty, arg, binding_mode)?; - } - Ok((current, current_else)) - } - - fn pattern_match_tuple_like( - &mut self, - current: BasicBlockId, - current_else: Option<BasicBlockId>, - args: &[PatId], - ellipsis: Option<usize>, - fields: impl DoubleEndedIterator<Item = (PlaceElem, Ty)> + Clone, - cond_place: &Place, - binding_mode: BindingAnnotation, - ) -> Result<(BasicBlockId, Option<BasicBlockId>)> { - let (al, ar) = args.split_at(ellipsis.unwrap_or(args.len())); - let it = al - .iter() - .zip(fields.clone()) - .chain(ar.iter().rev().zip(fields.rev())) - .map(|(x, y)| (y.0, *x, y.1)); - self.pattern_match_adt(current, current_else, it, cond_place, binding_mode) - } - fn discr_temp_place(&mut self) -> Place { match &self.discr_temp { Some(x) => x.clone(), @@ -1546,22 +1205,6 @@ impl MirLowerCtx<'_> { } } -fn pattern_matching_dereference( - cond_ty: &mut Ty, - binding_mode: &mut BindingAnnotation, - cond_place: &mut Place, -) { - while let Some((ty, _, mu)) = cond_ty.as_reference() { - if mu == Mutability::Mut && *binding_mode != BindingAnnotation::Ref { - *binding_mode = BindingAnnotation::RefMut; - } else { - *binding_mode = BindingAnnotation::Ref; - } - *cond_ty = ty.clone(); - cond_place.projection.push(ProjectionElem::Deref); - } -} - fn cast_kind(source_ty: &Ty, target_ty: &Ty) -> Result<CastKind> { Ok(match (source_ty.kind(Interner), target_ty.kind(Interner)) { (TyKind::Scalar(s), TyKind::Scalar(t)) => match (s, t) { |