737 lines
24 KiB
Rust
737 lines
24 KiB
Rust
//! The type system. We currently use this to infer types for completion, hover
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//! information and various assists.
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#![warn(rust_2018_idioms, unused_lifetimes)]
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#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
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#[allow(unused)]
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macro_rules! eprintln {
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($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
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}
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mod builder;
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mod chalk_db;
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mod chalk_ext;
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mod infer;
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mod inhabitedness;
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mod interner;
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mod lower;
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mod mapping;
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mod tls;
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mod utils;
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pub mod autoderef;
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pub mod consteval;
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pub mod db;
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pub mod diagnostics;
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pub mod display;
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pub mod lang_items;
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pub mod layout;
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pub mod method_resolution;
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pub mod mir;
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pub mod primitive;
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pub mod traits;
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#[cfg(test)]
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mod tests;
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#[cfg(test)]
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mod test_db;
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use std::{
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collections::{hash_map::Entry, HashMap},
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hash::Hash,
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};
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use chalk_ir::{
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fold::{Shift, TypeFoldable},
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interner::HasInterner,
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visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor},
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NoSolution, TyData,
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};
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use either::Either;
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use hir_def::{hir::ExprId, type_ref::Rawness, GeneralConstId, TypeOrConstParamId};
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use hir_expand::name;
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use la_arena::{Arena, Idx};
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use mir::{MirEvalError, VTableMap};
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use rustc_hash::FxHashSet;
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use syntax::ast::{make, ConstArg};
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use traits::FnTrait;
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use triomphe::Arc;
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use utils::Generics;
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use crate::{
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consteval::unknown_const, db::HirDatabase, display::HirDisplay, infer::unify::InferenceTable,
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utils::generics,
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};
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pub use autoderef::autoderef;
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pub use builder::{ParamKind, TyBuilder};
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pub use chalk_ext::*;
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pub use infer::{
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closure::{CaptureKind, CapturedItem},
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could_coerce, could_unify, Adjust, Adjustment, AutoBorrow, BindingMode, InferenceDiagnostic,
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InferenceResult, OverloadedDeref, PointerCast,
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};
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pub use interner::Interner;
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pub use lower::{
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associated_type_shorthand_candidates, CallableDefId, ImplTraitLoweringMode, ParamLoweringMode,
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TyDefId, TyLoweringContext, ValueTyDefId,
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};
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pub use mapping::{
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from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, from_placeholder_idx,
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lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id, to_foreign_def_id,
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to_placeholder_idx,
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};
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pub use method_resolution::check_orphan_rules;
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pub use traits::TraitEnvironment;
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pub use utils::{all_super_traits, is_fn_unsafe_to_call};
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pub use chalk_ir::{
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cast::Cast, AdtId, BoundVar, DebruijnIndex, Mutability, Safety, Scalar, TyVariableKind,
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};
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pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
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pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
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pub type FnDefId = chalk_ir::FnDefId<Interner>;
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pub type ClosureId = chalk_ir::ClosureId<Interner>;
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pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
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pub type PlaceholderIndex = chalk_ir::PlaceholderIndex;
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pub type VariableKind = chalk_ir::VariableKind<Interner>;
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pub type VariableKinds = chalk_ir::VariableKinds<Interner>;
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pub type CanonicalVarKinds = chalk_ir::CanonicalVarKinds<Interner>;
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/// Represents generic parameters and an item bound by them. When the item has parent, the binders
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/// also contain the generic parameters for its parent. See chalk's documentation for details.
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///
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/// One thing to keep in mind when working with `Binders` (and `Substitution`s, which represent
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/// generic arguments) in rust-analyzer is that the ordering within *is* significant - the generic
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/// parameters/arguments for an item MUST come before those for its parent. This is to facilitate
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/// the integration with chalk-solve, which mildly puts constraints as such. See #13335 for its
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/// motivation in detail.
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pub type Binders<T> = chalk_ir::Binders<T>;
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/// Interned list of generic arguments for an item. When an item has parent, the `Substitution` for
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/// it contains generic arguments for both its parent and itself. See chalk's documentation for
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/// details.
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///
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/// See `Binders` for the constraint on the ordering.
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pub type Substitution = chalk_ir::Substitution<Interner>;
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pub type GenericArg = chalk_ir::GenericArg<Interner>;
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pub type GenericArgData = chalk_ir::GenericArgData<Interner>;
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pub type Ty = chalk_ir::Ty<Interner>;
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pub type TyKind = chalk_ir::TyKind<Interner>;
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pub type TypeFlags = chalk_ir::TypeFlags;
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pub type DynTy = chalk_ir::DynTy<Interner>;
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pub type FnPointer = chalk_ir::FnPointer<Interner>;
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// pub type FnSubst = chalk_ir::FnSubst<Interner>; // a re-export so we don't lose the tuple constructor
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pub use chalk_ir::FnSubst;
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pub type ProjectionTy = chalk_ir::ProjectionTy<Interner>;
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pub type AliasTy = chalk_ir::AliasTy<Interner>;
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pub type OpaqueTy = chalk_ir::OpaqueTy<Interner>;
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pub type InferenceVar = chalk_ir::InferenceVar;
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pub type Lifetime = chalk_ir::Lifetime<Interner>;
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pub type LifetimeData = chalk_ir::LifetimeData<Interner>;
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pub type LifetimeOutlives = chalk_ir::LifetimeOutlives<Interner>;
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pub type Const = chalk_ir::Const<Interner>;
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pub type ConstData = chalk_ir::ConstData<Interner>;
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pub type ConstValue = chalk_ir::ConstValue<Interner>;
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pub type ConcreteConst = chalk_ir::ConcreteConst<Interner>;
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pub type ChalkTraitId = chalk_ir::TraitId<Interner>;
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pub type TraitRef = chalk_ir::TraitRef<Interner>;
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pub type QuantifiedWhereClause = Binders<WhereClause>;
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pub type QuantifiedWhereClauses = chalk_ir::QuantifiedWhereClauses<Interner>;
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pub type Canonical<T> = chalk_ir::Canonical<T>;
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pub type FnSig = chalk_ir::FnSig<Interner>;
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pub type InEnvironment<T> = chalk_ir::InEnvironment<T>;
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pub type Environment = chalk_ir::Environment<Interner>;
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pub type DomainGoal = chalk_ir::DomainGoal<Interner>;
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pub type Goal = chalk_ir::Goal<Interner>;
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pub type AliasEq = chalk_ir::AliasEq<Interner>;
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pub type Solution = chalk_solve::Solution<Interner>;
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pub type ConstrainedSubst = chalk_ir::ConstrainedSubst<Interner>;
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pub type Guidance = chalk_solve::Guidance<Interner>;
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pub type WhereClause = chalk_ir::WhereClause<Interner>;
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/// A constant can have reference to other things. Memory map job is holding
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/// the necessary bits of memory of the const eval session to keep the constant
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/// meaningful.
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#[derive(Debug, Default, Clone, PartialEq, Eq)]
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pub struct MemoryMap {
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pub memory: HashMap<usize, Vec<u8>>,
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pub vtable: VTableMap,
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}
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impl MemoryMap {
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fn insert(&mut self, addr: usize, x: Vec<u8>) {
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match self.memory.entry(addr) {
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Entry::Occupied(mut e) => {
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if e.get().len() < x.len() {
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e.insert(x);
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}
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}
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Entry::Vacant(e) => {
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e.insert(x);
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}
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}
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}
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/// This functions convert each address by a function `f` which gets the byte intervals and assign an address
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/// to them. It is useful when you want to load a constant with a memory map in a new memory. You can pass an
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/// allocator function as `f` and it will return a mapping of old addresses to new addresses.
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fn transform_addresses(
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&self,
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mut f: impl FnMut(&[u8], usize) -> Result<usize, MirEvalError>,
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) -> Result<HashMap<usize, usize>, MirEvalError> {
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self.memory
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.iter()
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.map(|x| {
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let addr = *x.0;
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let align = if addr == 0 { 64 } else { (addr - (addr & (addr - 1))).min(64) };
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Ok((addr, f(x.1, align)?))
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})
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.collect()
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}
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fn get<'a>(&'a self, addr: usize, size: usize) -> Option<&'a [u8]> {
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if size == 0 {
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Some(&[])
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} else {
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self.memory.get(&addr)?.get(0..size)
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}
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}
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}
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/// A concrete constant value
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#[derive(Debug, Clone, PartialEq, Eq)]
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pub enum ConstScalar {
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Bytes(Vec<u8>, MemoryMap),
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// FIXME: this is a hack to get around chalk not being able to represent unevaluatable
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// constants
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UnevaluatedConst(GeneralConstId, Substitution),
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/// Case of an unknown value that rustc might know but we don't
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// FIXME: this is a hack to get around chalk not being able to represent unevaluatable
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// constants
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// https://github.com/rust-lang/rust-analyzer/pull/8813#issuecomment-840679177
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// https://rust-lang.zulipchat.com/#narrow/stream/144729-wg-traits/topic/Handling.20non.20evaluatable.20constants'.20equality/near/238386348
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Unknown,
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}
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impl Hash for ConstScalar {
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fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
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core::mem::discriminant(self).hash(state);
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if let ConstScalar::Bytes(b, _) = self {
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b.hash(state)
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}
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}
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}
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/// Return an index of a parameter in the generic type parameter list by it's id.
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pub fn param_idx(db: &dyn HirDatabase, id: TypeOrConstParamId) -> Option<usize> {
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generics(db.upcast(), id.parent).param_idx(id)
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}
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pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
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where
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T: TypeFoldable<Interner> + HasInterner<Interner = Interner>,
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{
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Binders::empty(Interner, value.shifted_in_from(Interner, DebruijnIndex::ONE))
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}
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pub(crate) fn make_type_and_const_binders<T: HasInterner<Interner = Interner>>(
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which_is_const: impl Iterator<Item = Option<Ty>>,
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value: T,
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) -> Binders<T> {
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Binders::new(
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VariableKinds::from_iter(
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Interner,
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which_is_const.map(|x| {
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if let Some(ty) = x {
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chalk_ir::VariableKind::Const(ty)
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} else {
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chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)
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}
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}),
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),
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value,
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)
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}
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pub(crate) fn make_single_type_binders<T: HasInterner<Interner = Interner>>(
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value: T,
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) -> Binders<T> {
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Binders::new(
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VariableKinds::from_iter(
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Interner,
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std::iter::once(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)),
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),
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value,
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)
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}
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pub(crate) fn make_binders_with_count<T: HasInterner<Interner = Interner>>(
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db: &dyn HirDatabase,
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count: usize,
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generics: &Generics,
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value: T,
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) -> Binders<T> {
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let it = generics.iter_id().take(count).map(|id| match id {
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Either::Left(_) => None,
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Either::Right(id) => Some(db.const_param_ty(id)),
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});
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crate::make_type_and_const_binders(it, value)
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}
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pub(crate) fn make_binders<T: HasInterner<Interner = Interner>>(
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db: &dyn HirDatabase,
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generics: &Generics,
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value: T,
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) -> Binders<T> {
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make_binders_with_count(db, usize::MAX, generics, value)
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}
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// FIXME: get rid of this, just replace it by FnPointer
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/// A function signature as seen by type inference: Several parameter types and
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/// one return type.
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#[derive(Clone, PartialEq, Eq, Debug)]
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pub struct CallableSig {
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params_and_return: Arc<[Ty]>,
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is_varargs: bool,
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safety: Safety,
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}
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has_interner!(CallableSig);
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/// A polymorphic function signature.
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pub type PolyFnSig = Binders<CallableSig>;
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impl CallableSig {
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pub fn from_params_and_return(
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mut params: Vec<Ty>,
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ret: Ty,
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is_varargs: bool,
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safety: Safety,
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) -> CallableSig {
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params.push(ret);
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CallableSig { params_and_return: params.into(), is_varargs, safety }
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}
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pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
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CallableSig {
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// FIXME: what to do about lifetime params? -> return PolyFnSig
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params_and_return: Arc::from_iter(
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fn_ptr
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.substitution
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.clone()
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.shifted_out_to(Interner, DebruijnIndex::ONE)
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.expect("unexpected lifetime vars in fn ptr")
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.0
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.as_slice(Interner)
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.iter()
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.map(|arg| arg.assert_ty_ref(Interner).clone()),
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),
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is_varargs: fn_ptr.sig.variadic,
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safety: fn_ptr.sig.safety,
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}
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}
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pub fn to_fn_ptr(&self) -> FnPointer {
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FnPointer {
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num_binders: 0,
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sig: FnSig { abi: (), safety: self.safety, variadic: self.is_varargs },
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substitution: FnSubst(Substitution::from_iter(
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Interner,
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self.params_and_return.iter().cloned(),
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)),
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}
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}
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pub fn params(&self) -> &[Ty] {
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&self.params_and_return[0..self.params_and_return.len() - 1]
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}
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pub fn ret(&self) -> &Ty {
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&self.params_and_return[self.params_and_return.len() - 1]
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}
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}
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impl TypeFoldable<Interner> for CallableSig {
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fn try_fold_with<E>(
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self,
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folder: &mut dyn chalk_ir::fold::FallibleTypeFolder<Interner, Error = E>,
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outer_binder: DebruijnIndex,
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) -> Result<Self, E> {
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let vec = self.params_and_return.to_vec();
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let folded = vec.try_fold_with(folder, outer_binder)?;
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Ok(CallableSig {
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params_and_return: folded.into(),
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is_varargs: self.is_varargs,
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safety: self.safety,
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})
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}
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}
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#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
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pub enum ImplTraitId {
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ReturnTypeImplTrait(hir_def::FunctionId, RpitId),
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AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
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}
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#[derive(Clone, PartialEq, Eq, Debug, Hash)]
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pub struct ReturnTypeImplTraits {
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pub(crate) impl_traits: Arena<ReturnTypeImplTrait>,
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}
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has_interner!(ReturnTypeImplTraits);
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#[derive(Clone, PartialEq, Eq, Debug, Hash)]
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pub struct ReturnTypeImplTrait {
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pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
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}
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pub type RpitId = Idx<ReturnTypeImplTrait>;
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pub fn static_lifetime() -> Lifetime {
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LifetimeData::Static.intern(Interner)
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}
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pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
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t: T,
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for_ty: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
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for_const: impl FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
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) -> T {
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use chalk_ir::fold::TypeFolder;
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#[derive(chalk_derive::FallibleTypeFolder)]
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#[has_interner(Interner)]
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struct FreeVarFolder<
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F1: FnMut(BoundVar, DebruijnIndex) -> Ty,
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F2: FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
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>(F1, F2);
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impl<
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F1: FnMut(BoundVar, DebruijnIndex) -> Ty,
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F2: FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
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> TypeFolder<Interner> for FreeVarFolder<F1, F2>
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{
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fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner, Error = Self::Error> {
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self
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}
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fn interner(&self) -> Interner {
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Interner
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}
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fn fold_free_var_ty(&mut self, bound_var: BoundVar, outer_binder: DebruijnIndex) -> Ty {
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self.0(bound_var, outer_binder)
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}
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fn fold_free_var_const(
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&mut self,
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ty: Ty,
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bound_var: BoundVar,
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outer_binder: DebruijnIndex,
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) -> Const {
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self.1(ty, bound_var, outer_binder)
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}
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}
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t.fold_with(&mut FreeVarFolder(for_ty, for_const), DebruijnIndex::INNERMOST)
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}
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pub(crate) fn fold_tys<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
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t: T,
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mut for_ty: impl FnMut(Ty, DebruijnIndex) -> Ty,
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binders: DebruijnIndex,
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) -> T {
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fold_tys_and_consts(
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t,
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|x, d| match x {
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Either::Left(x) => Either::Left(for_ty(x, d)),
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Either::Right(x) => Either::Right(x),
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},
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binders,
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)
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}
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pub(crate) fn fold_tys_and_consts<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
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t: T,
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f: impl FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>,
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binders: DebruijnIndex,
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) -> T {
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use chalk_ir::fold::{TypeFolder, TypeSuperFoldable};
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#[derive(chalk_derive::FallibleTypeFolder)]
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#[has_interner(Interner)]
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struct TyFolder<F: FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>>(F);
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impl<F: FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>> TypeFolder<Interner>
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for TyFolder<F>
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{
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fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner, Error = Self::Error> {
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self
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|
}
|
|
|
|
fn interner(&self) -> Interner {
|
|
Interner
|
|
}
|
|
|
|
fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Ty {
|
|
let ty = ty.super_fold_with(self.as_dyn(), outer_binder);
|
|
self.0(Either::Left(ty), outer_binder).left().unwrap()
|
|
}
|
|
|
|
fn fold_const(&mut self, c: Const, outer_binder: DebruijnIndex) -> Const {
|
|
self.0(Either::Right(c), outer_binder).right().unwrap()
|
|
}
|
|
}
|
|
t.fold_with(&mut TyFolder(f), binders)
|
|
}
|
|
|
|
/// 'Canonicalizes' the `t` by replacing any errors with new variables. Also
|
|
/// ensures there are no unbound variables or inference variables anywhere in
|
|
/// the `t`.
|
|
pub fn replace_errors_with_variables<T>(t: &T) -> Canonical<T>
|
|
where
|
|
T: HasInterner<Interner = Interner> + TypeFoldable<Interner> + Clone,
|
|
{
|
|
use chalk_ir::{
|
|
fold::{FallibleTypeFolder, TypeSuperFoldable},
|
|
Fallible,
|
|
};
|
|
struct ErrorReplacer {
|
|
vars: usize,
|
|
}
|
|
impl FallibleTypeFolder<Interner> for ErrorReplacer {
|
|
type Error = NoSolution;
|
|
|
|
fn as_dyn(&mut self) -> &mut dyn FallibleTypeFolder<Interner, Error = Self::Error> {
|
|
self
|
|
}
|
|
|
|
fn interner(&self) -> Interner {
|
|
Interner
|
|
}
|
|
|
|
fn try_fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
|
|
if let TyKind::Error = ty.kind(Interner) {
|
|
let index = self.vars;
|
|
self.vars += 1;
|
|
Ok(TyKind::BoundVar(BoundVar::new(outer_binder, index)).intern(Interner))
|
|
} else {
|
|
ty.try_super_fold_with(self.as_dyn(), outer_binder)
|
|
}
|
|
}
|
|
|
|
fn try_fold_inference_ty(
|
|
&mut self,
|
|
_var: InferenceVar,
|
|
_kind: TyVariableKind,
|
|
_outer_binder: DebruijnIndex,
|
|
) -> Fallible<Ty> {
|
|
if cfg!(debug_assertions) {
|
|
// we don't want to just panic here, because then the error message
|
|
// won't contain the whole thing, which would not be very helpful
|
|
Err(NoSolution)
|
|
} else {
|
|
Ok(TyKind::Error.intern(Interner))
|
|
}
|
|
}
|
|
|
|
fn try_fold_free_var_ty(
|
|
&mut self,
|
|
_bound_var: BoundVar,
|
|
_outer_binder: DebruijnIndex,
|
|
) -> Fallible<Ty> {
|
|
if cfg!(debug_assertions) {
|
|
// we don't want to just panic here, because then the error message
|
|
// won't contain the whole thing, which would not be very helpful
|
|
Err(NoSolution)
|
|
} else {
|
|
Ok(TyKind::Error.intern(Interner))
|
|
}
|
|
}
|
|
|
|
fn try_fold_inference_const(
|
|
&mut self,
|
|
ty: Ty,
|
|
_var: InferenceVar,
|
|
_outer_binder: DebruijnIndex,
|
|
) -> Fallible<Const> {
|
|
if cfg!(debug_assertions) {
|
|
Err(NoSolution)
|
|
} else {
|
|
Ok(unknown_const(ty))
|
|
}
|
|
}
|
|
|
|
fn try_fold_free_var_const(
|
|
&mut self,
|
|
ty: Ty,
|
|
_bound_var: BoundVar,
|
|
_outer_binder: DebruijnIndex,
|
|
) -> Fallible<Const> {
|
|
if cfg!(debug_assertions) {
|
|
Err(NoSolution)
|
|
} else {
|
|
Ok(unknown_const(ty))
|
|
}
|
|
}
|
|
|
|
fn try_fold_inference_lifetime(
|
|
&mut self,
|
|
_var: InferenceVar,
|
|
_outer_binder: DebruijnIndex,
|
|
) -> Fallible<Lifetime> {
|
|
if cfg!(debug_assertions) {
|
|
Err(NoSolution)
|
|
} else {
|
|
Ok(static_lifetime())
|
|
}
|
|
}
|
|
|
|
fn try_fold_free_var_lifetime(
|
|
&mut self,
|
|
_bound_var: BoundVar,
|
|
_outer_binder: DebruijnIndex,
|
|
) -> Fallible<Lifetime> {
|
|
if cfg!(debug_assertions) {
|
|
Err(NoSolution)
|
|
} else {
|
|
Ok(static_lifetime())
|
|
}
|
|
}
|
|
}
|
|
let mut error_replacer = ErrorReplacer { vars: 0 };
|
|
let value = match t.clone().try_fold_with(&mut error_replacer, DebruijnIndex::INNERMOST) {
|
|
Ok(t) => t,
|
|
Err(_) => panic!("Encountered unbound or inference vars in {t:?}"),
|
|
};
|
|
let kinds = (0..error_replacer.vars).map(|_| {
|
|
chalk_ir::CanonicalVarKind::new(
|
|
chalk_ir::VariableKind::Ty(TyVariableKind::General),
|
|
chalk_ir::UniverseIndex::ROOT,
|
|
)
|
|
});
|
|
Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(Interner, kinds) }
|
|
}
|
|
|
|
pub fn callable_sig_from_fnonce(
|
|
mut self_ty: &Ty,
|
|
env: Arc<TraitEnvironment>,
|
|
db: &dyn HirDatabase,
|
|
) -> Option<CallableSig> {
|
|
if let Some((ty, _, _)) = self_ty.as_reference() {
|
|
// This will happen when it implements fn or fn mut, since we add a autoborrow adjustment
|
|
self_ty = ty;
|
|
}
|
|
let krate = env.krate;
|
|
let fn_once_trait = FnTrait::FnOnce.get_id(db, krate)?;
|
|
let output_assoc_type = db.trait_data(fn_once_trait).associated_type_by_name(&name![Output])?;
|
|
|
|
let mut table = InferenceTable::new(db, env);
|
|
let b = TyBuilder::trait_ref(db, fn_once_trait);
|
|
if b.remaining() != 2 {
|
|
return None;
|
|
}
|
|
|
|
// Register two obligations:
|
|
// - Self: FnOnce<?args_ty>
|
|
// - <Self as FnOnce<?args_ty>>::Output == ?ret_ty
|
|
let args_ty = table.new_type_var();
|
|
let trait_ref = b.push(self_ty.clone()).push(args_ty.clone()).build();
|
|
let projection = TyBuilder::assoc_type_projection(
|
|
db,
|
|
output_assoc_type,
|
|
Some(trait_ref.substitution.clone()),
|
|
)
|
|
.build();
|
|
table.register_obligation(trait_ref.cast(Interner));
|
|
let ret_ty = table.normalize_projection_ty(projection);
|
|
|
|
let ret_ty = table.resolve_completely(ret_ty);
|
|
let args_ty = table.resolve_completely(args_ty);
|
|
|
|
let params =
|
|
args_ty.as_tuple()?.iter(Interner).map(|it| it.assert_ty_ref(Interner)).cloned().collect();
|
|
|
|
Some(CallableSig::from_params_and_return(params, ret_ty, false, Safety::Safe))
|
|
}
|
|
|
|
struct PlaceholderCollector<'db> {
|
|
db: &'db dyn HirDatabase,
|
|
placeholders: FxHashSet<TypeOrConstParamId>,
|
|
}
|
|
|
|
impl PlaceholderCollector<'_> {
|
|
fn collect(&mut self, idx: PlaceholderIndex) {
|
|
let id = from_placeholder_idx(self.db, idx);
|
|
self.placeholders.insert(id);
|
|
}
|
|
}
|
|
|
|
impl TypeVisitor<Interner> for PlaceholderCollector<'_> {
|
|
type BreakTy = ();
|
|
|
|
fn as_dyn(&mut self) -> &mut dyn TypeVisitor<Interner, BreakTy = Self::BreakTy> {
|
|
self
|
|
}
|
|
|
|
fn interner(&self) -> Interner {
|
|
Interner
|
|
}
|
|
|
|
fn visit_ty(
|
|
&mut self,
|
|
ty: &Ty,
|
|
outer_binder: DebruijnIndex,
|
|
) -> std::ops::ControlFlow<Self::BreakTy> {
|
|
let has_placeholder_bits = TypeFlags::HAS_TY_PLACEHOLDER | TypeFlags::HAS_CT_PLACEHOLDER;
|
|
let TyData { kind, flags } = ty.data(Interner);
|
|
|
|
if let TyKind::Placeholder(idx) = kind {
|
|
self.collect(*idx);
|
|
} else if flags.intersects(has_placeholder_bits) {
|
|
return ty.super_visit_with(self, outer_binder);
|
|
} else {
|
|
// Fast path: don't visit inner types (e.g. generic arguments) when `flags` indicate
|
|
// that there are no placeholders.
|
|
}
|
|
|
|
std::ops::ControlFlow::Continue(())
|
|
}
|
|
|
|
fn visit_const(
|
|
&mut self,
|
|
constant: &chalk_ir::Const<Interner>,
|
|
_outer_binder: DebruijnIndex,
|
|
) -> std::ops::ControlFlow<Self::BreakTy> {
|
|
if let chalk_ir::ConstValue::Placeholder(idx) = constant.data(Interner).value {
|
|
self.collect(idx);
|
|
}
|
|
std::ops::ControlFlow::Continue(())
|
|
}
|
|
}
|
|
|
|
/// Returns unique placeholders for types and consts contained in `value`.
|
|
pub fn collect_placeholders<T>(value: &T, db: &dyn HirDatabase) -> Vec<TypeOrConstParamId>
|
|
where
|
|
T: ?Sized + TypeVisitable<Interner>,
|
|
{
|
|
let mut collector = PlaceholderCollector { db, placeholders: FxHashSet::default() };
|
|
value.visit_with(&mut collector, DebruijnIndex::INNERMOST);
|
|
collector.placeholders.into_iter().collect()
|
|
}
|
|
|
|
pub fn known_const_to_ast(konst: &Const, db: &dyn HirDatabase) -> Option<ConstArg> {
|
|
if let ConstValue::Concrete(c) = &konst.interned().value {
|
|
match c.interned {
|
|
ConstScalar::UnevaluatedConst(GeneralConstId::InTypeConstId(cid), _) => {
|
|
return Some(cid.source(db.upcast()));
|
|
}
|
|
ConstScalar::Unknown => return None,
|
|
_ => (),
|
|
}
|
|
}
|
|
Some(make::expr_const_value(konst.display(db).to_string().as_str()))
|
|
}
|