diff --git a/Cargo.lock b/Cargo.lock index 4c255b12b7..59cd66756c 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -557,6 +557,7 @@ version = "0.0.0" dependencies = [ "arrayvec", "base-db", + "bitflags", "chalk-derive", "chalk-ir", "chalk-recursive", diff --git a/crates/hir-ty/Cargo.toml b/crates/hir-ty/Cargo.toml index c72199c37f..ae837ac6dc 100644 --- a/crates/hir-ty/Cargo.toml +++ b/crates/hir-ty/Cargo.toml @@ -13,6 +13,7 @@ doctest = false cov-mark = "2.0.0-pre.1" itertools = "0.10.5" arrayvec = "0.7.2" +bitflags = "1.3.2" smallvec = "1.10.0" ena = "0.14.0" tracing = "0.1.35" diff --git a/crates/hir-ty/src/infer/unify.rs b/crates/hir-ty/src/infer/unify.rs index 12f45f00f9..c4488d6d91 100644 --- a/crates/hir-ty/src/infer/unify.rs +++ b/crates/hir-ty/src/infer/unify.rs @@ -1,6 +1,6 @@ //! Unification and canonicalization logic. -use std::{fmt, mem, sync::Arc}; +use std::{fmt, iter, mem, sync::Arc}; use chalk_ir::{ cast::Cast, fold::TypeFoldable, interner::HasInterner, zip::Zip, CanonicalVarKind, FloatTy, @@ -128,9 +128,11 @@ pub(crate) fn unify( )) } -#[derive(Copy, Clone, Debug)] -pub(crate) struct TypeVariableData { - diverging: bool, +bitflags::bitflags! { + #[derive(Default)] + pub(crate) struct TypeVariableFlags: u8 { + const DIVERGING = 1 << 0; + } } type ChalkInferenceTable = chalk_solve::infer::InferenceTable; @@ -140,14 +142,14 @@ pub(crate) struct InferenceTable<'a> { pub(crate) db: &'a dyn HirDatabase, pub(crate) trait_env: Arc, var_unification_table: ChalkInferenceTable, - type_variable_table: Vec, + type_variable_table: Vec, pending_obligations: Vec>>, } pub(crate) struct InferenceTableSnapshot { var_table_snapshot: chalk_solve::infer::InferenceSnapshot, pending_obligations: Vec>>, - type_variable_table_snapshot: Vec, + type_variable_table_snapshot: Vec, } impl<'a> InferenceTable<'a> { @@ -169,19 +171,19 @@ impl<'a> InferenceTable<'a> { /// result. pub(super) fn propagate_diverging_flag(&mut self) { for i in 0..self.type_variable_table.len() { - if !self.type_variable_table[i].diverging { + if !self.type_variable_table[i].contains(TypeVariableFlags::DIVERGING) { continue; } let v = InferenceVar::from(i as u32); let root = self.var_unification_table.inference_var_root(v); if let Some(data) = self.type_variable_table.get_mut(root.index() as usize) { - data.diverging = true; + *data |= TypeVariableFlags::DIVERGING; } } } pub(super) fn set_diverging(&mut self, iv: InferenceVar, diverging: bool) { - self.type_variable_table[iv.index() as usize].diverging = diverging; + self.type_variable_table[iv.index() as usize].set(TypeVariableFlags::DIVERGING, diverging); } fn fallback_value(&self, iv: InferenceVar, kind: TyVariableKind) -> Ty { @@ -189,7 +191,7 @@ impl<'a> InferenceTable<'a> { _ if self .type_variable_table .get(iv.index() as usize) - .map_or(false, |data| data.diverging) => + .map_or(false, |data| data.contains(TypeVariableFlags::DIVERGING)) => { TyKind::Never } @@ -247,10 +249,8 @@ impl<'a> InferenceTable<'a> { } fn extend_type_variable_table(&mut self, to_index: usize) { - self.type_variable_table.extend( - (0..1 + to_index - self.type_variable_table.len()) - .map(|_| TypeVariableData { diverging: false }), - ); + let count = to_index - self.type_variable_table.len() + 1; + self.type_variable_table.extend(iter::repeat(TypeVariableFlags::default()).take(count)); } fn new_var(&mut self, kind: TyVariableKind, diverging: bool) -> Ty { @@ -258,7 +258,9 @@ impl<'a> InferenceTable<'a> { // Chalk might have created some type variables for its own purposes that we don't know about... self.extend_type_variable_table(var.index() as usize); assert_eq!(var.index() as usize, self.type_variable_table.len() - 1); - self.type_variable_table[var.index() as usize].diverging = diverging; + if diverging { + self.type_variable_table[var.index() as usize] |= TypeVariableFlags::DIVERGING; + } var.to_ty_with_kind(Interner, kind) }