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//! The type system. We currently use this to infer types for completion, hover
//! information and various assists.
#![warn(rust_2018_idioms, unused_lifetimes)]
#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
#[cfg(feature = "in-rust-tree")]
extern crate rustc_index;
#[cfg(not(feature = "in-rust-tree"))]
extern crate ra_ap_rustc_index as rustc_index;
#[cfg(feature = "in-rust-tree")]
extern crate rustc_abi;
#[cfg(not(feature = "in-rust-tree"))]
extern crate ra_ap_rustc_abi as rustc_abi;
mod builder;
mod chalk_db;
mod chalk_ext;
mod infer;
mod inhabitedness;
mod interner;
mod lower;
mod mapping;
mod tls;
mod utils;
pub mod autoderef;
pub mod consteval;
pub mod db;
pub mod diagnostics;
pub mod display;
pub mod lang_items;
pub mod layout;
pub mod method_resolution;
pub mod mir;
pub mod primitive;
pub mod traits;
#[cfg(test)]
mod tests;
#[cfg(test)]
mod test_db;
use std::{
collections::hash_map::Entry,
hash::{BuildHasherDefault, Hash},
};
use chalk_ir::{
fold::{Shift, TypeFoldable},
interner::HasInterner,
visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor},
NoSolution,
};
use either::Either;
use hir_def::{hir::ExprId, type_ref::Rawness, GeneralConstId, TypeOrConstParamId};
use hir_expand::name;
use la_arena::{Arena, Idx};
use mir::{MirEvalError, VTableMap};
use rustc_hash::{FxHashMap, FxHashSet};
use syntax::ast::{make, ConstArg};
use traits::FnTrait;
use triomphe::Arc;
use utils::Generics;
use crate::{
consteval::unknown_const, db::HirDatabase, display::HirDisplay, infer::unify::InferenceTable,
utils::generics,
};
pub use autoderef::autoderef;
pub use builder::{ParamKind, TyBuilder};
pub use chalk_ext::*;
pub use infer::{
closure::{CaptureKind, CapturedItem},
could_coerce, could_unify, Adjust, Adjustment, AutoBorrow, BindingMode, InferenceDiagnostic,
InferenceResult, OverloadedDeref, PointerCast,
};
pub use interner::Interner;
pub use lower::{
associated_type_shorthand_candidates, CallableDefId, ImplTraitLoweringMode, ParamLoweringMode,
TyDefId, TyLoweringContext, ValueTyDefId,
};
pub use mapping::{
from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, from_placeholder_idx,
lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id, to_foreign_def_id,
to_placeholder_idx,
};
pub use method_resolution::check_orphan_rules;
pub use traits::TraitEnvironment;
pub use utils::{all_super_traits, is_fn_unsafe_to_call};
pub use chalk_ir::{
cast::Cast, AdtId, BoundVar, DebruijnIndex, Mutability, Safety, Scalar, TyVariableKind,
};
pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
pub type FnDefId = chalk_ir::FnDefId<Interner>;
pub type ClosureId = chalk_ir::ClosureId<Interner>;
pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
pub type PlaceholderIndex = chalk_ir::PlaceholderIndex;
pub type VariableKind = chalk_ir::VariableKind<Interner>;
pub type VariableKinds = chalk_ir::VariableKinds<Interner>;
pub type CanonicalVarKinds = chalk_ir::CanonicalVarKinds<Interner>;
/// Represents generic parameters and an item bound by them. When the item has parent, the binders
/// also contain the generic parameters for its parent. See chalk's documentation for details.
///
/// One thing to keep in mind when working with `Binders` (and `Substitution`s, which represent
/// generic arguments) in rust-analyzer is that the ordering within *is* significant - the generic
/// parameters/arguments for an item MUST come before those for its parent. This is to facilitate
/// the integration with chalk-solve, which mildly puts constraints as such. See #13335 for its
/// motivation in detail.
pub type Binders<T> = chalk_ir::Binders<T>;
/// Interned list of generic arguments for an item. When an item has parent, the `Substitution` for
/// it contains generic arguments for both its parent and itself. See chalk's documentation for
/// details.
///
/// See `Binders` for the constraint on the ordering.
pub type Substitution = chalk_ir::Substitution<Interner>;
pub type GenericArg = chalk_ir::GenericArg<Interner>;
pub type GenericArgData = chalk_ir::GenericArgData<Interner>;
pub type Ty = chalk_ir::Ty<Interner>;
pub type TyKind = chalk_ir::TyKind<Interner>;
pub type TypeFlags = chalk_ir::TypeFlags;
pub type DynTy = chalk_ir::DynTy<Interner>;
pub type FnPointer = chalk_ir::FnPointer<Interner>;
// pub type FnSubst = chalk_ir::FnSubst<Interner>; // a re-export so we don't lose the tuple constructor
pub use chalk_ir::FnSubst;
pub type ProjectionTy = chalk_ir::ProjectionTy<Interner>;
pub type AliasTy = chalk_ir::AliasTy<Interner>;
pub type OpaqueTy = chalk_ir::OpaqueTy<Interner>;
pub type InferenceVar = chalk_ir::InferenceVar;
pub type Lifetime = chalk_ir::Lifetime<Interner>;
pub type LifetimeData = chalk_ir::LifetimeData<Interner>;
pub type LifetimeOutlives = chalk_ir::LifetimeOutlives<Interner>;
pub type Const = chalk_ir::Const<Interner>;
pub type ConstData = chalk_ir::ConstData<Interner>;
pub type ConstValue = chalk_ir::ConstValue<Interner>;
pub type ConcreteConst = chalk_ir::ConcreteConst<Interner>;
pub type ChalkTraitId = chalk_ir::TraitId<Interner>;
pub type TraitRef = chalk_ir::TraitRef<Interner>;
pub type QuantifiedWhereClause = Binders<WhereClause>;
pub type QuantifiedWhereClauses = chalk_ir::QuantifiedWhereClauses<Interner>;
pub type Canonical<T> = chalk_ir::Canonical<T>;
pub type FnSig = chalk_ir::FnSig<Interner>;
pub type InEnvironment<T> = chalk_ir::InEnvironment<T>;
pub type Environment = chalk_ir::Environment<Interner>;
pub type DomainGoal = chalk_ir::DomainGoal<Interner>;
pub type Goal = chalk_ir::Goal<Interner>;
pub type AliasEq = chalk_ir::AliasEq<Interner>;
pub type Solution = chalk_solve::Solution<Interner>;
pub type Constraint = chalk_ir::Constraint<Interner>;
pub type Constraints = chalk_ir::Constraints<Interner>;
pub type ConstrainedSubst = chalk_ir::ConstrainedSubst<Interner>;
pub type Guidance = chalk_solve::Guidance<Interner>;
pub type WhereClause = chalk_ir::WhereClause<Interner>;
pub type CanonicalVarKind = chalk_ir::CanonicalVarKind<Interner>;
pub type GoalData = chalk_ir::GoalData<Interner>;
pub type Goals = chalk_ir::Goals<Interner>;
pub type ProgramClauseData = chalk_ir::ProgramClauseData<Interner>;
pub type ProgramClause = chalk_ir::ProgramClause<Interner>;
pub type ProgramClauses = chalk_ir::ProgramClauses<Interner>;
pub type TyData = chalk_ir::TyData<Interner>;
pub type Variances = chalk_ir::Variances<Interner>;
/// A constant can have reference to other things. Memory map job is holding
/// the necessary bits of memory of the const eval session to keep the constant
/// meaningful.
#[derive(Debug, Default, Clone, PartialEq, Eq)]
pub enum MemoryMap {
#[default]
Empty,
Simple(Box<[u8]>),
Complex(Box<ComplexMemoryMap>),
}
#[derive(Debug, Default, Clone, PartialEq, Eq)]
pub struct ComplexMemoryMap {
memory: FxHashMap<usize, Box<[u8]>>,
vtable: VTableMap,
}
impl ComplexMemoryMap {
fn insert(&mut self, addr: usize, val: Box<[u8]>) {
match self.memory.entry(addr) {
Entry::Occupied(mut e) => {
if e.get().len() < val.len() {
e.insert(val);
}
}
Entry::Vacant(e) => {
e.insert(val);
}
}
}
}
impl MemoryMap {
pub fn vtable_ty(&self, id: usize) -> Result<&Ty, MirEvalError> {
match self {
MemoryMap::Empty | MemoryMap::Simple(_) => Err(MirEvalError::InvalidVTableId(id)),
MemoryMap::Complex(cm) => cm.vtable.ty(id),
}
}
fn simple(v: Box<[u8]>) -> Self {
MemoryMap::Simple(v)
}
/// This functions convert each address by a function `f` which gets the byte intervals and assign an address
/// to them. It is useful when you want to load a constant with a memory map in a new memory. You can pass an
/// allocator function as `f` and it will return a mapping of old addresses to new addresses.
fn transform_addresses(
&self,
mut f: impl FnMut(&[u8], usize) -> Result<usize, MirEvalError>,
) -> Result<FxHashMap<usize, usize>, MirEvalError> {
let mut transform = |(addr, val): (&usize, &Box<[u8]>)| {
let addr = *addr;
let align = if addr == 0 { 64 } else { (addr - (addr & (addr - 1))).min(64) };
f(val, align).map(|it| (addr, it))
};
match self {
MemoryMap::Empty => Ok(Default::default()),
MemoryMap::Simple(m) => transform((&0, m)).map(|(addr, val)| {
let mut map = FxHashMap::with_capacity_and_hasher(1, BuildHasherDefault::default());
map.insert(addr, val);
map
}),
MemoryMap::Complex(cm) => cm.memory.iter().map(transform).collect(),
}
}
fn get(&self, addr: usize, size: usize) -> Option<&[u8]> {
if size == 0 {
Some(&[])
} else {
match self {
MemoryMap::Empty => Some(&[]),
MemoryMap::Simple(m) if addr == 0 => m.get(0..size),
MemoryMap::Simple(_) => None,
MemoryMap::Complex(cm) => cm.memory.get(&addr)?.get(0..size),
}
}
}
}
/// A concrete constant value
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ConstScalar {
Bytes(Box<[u8]>, MemoryMap),
// FIXME: this is a hack to get around chalk not being able to represent unevaluatable
// constants
UnevaluatedConst(GeneralConstId, Substitution),
/// Case of an unknown value that rustc might know but we don't
// FIXME: this is a hack to get around chalk not being able to represent unevaluatable
// constants
// https://github.com/rust-lang/rust-analyzer/pull/8813#issuecomment-840679177
// https://rust-lang.zulipchat.com/#narrow/stream/144729-wg-traits/topic/Handling.20non.20evaluatable.20constants'.20equality/near/238386348
Unknown,
}
impl Hash for ConstScalar {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
core::mem::discriminant(self).hash(state);
if let ConstScalar::Bytes(b, _) = self {
b.hash(state)
}
}
}
/// Return an index of a parameter in the generic type parameter list by it's id.
pub fn param_idx(db: &dyn HirDatabase, id: TypeOrConstParamId) -> Option<usize> {
generics(db.upcast(), id.parent).param_idx(id)
}
pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
where
T: TypeFoldable<Interner> + HasInterner<Interner = Interner>,
{
Binders::empty(Interner, value.shifted_in_from(Interner, DebruijnIndex::ONE))
}
pub(crate) fn make_type_and_const_binders<T: HasInterner<Interner = Interner>>(
which_is_const: impl Iterator<Item = Option<Ty>>,
value: T,
) -> Binders<T> {
Binders::new(
VariableKinds::from_iter(
Interner,
which_is_const.map(|x| {
if let Some(ty) = x {
chalk_ir::VariableKind::Const(ty)
} else {
chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)
}
}),
),
value,
)
}
pub(crate) fn make_single_type_binders<T: HasInterner<Interner = Interner>>(
value: T,
) -> Binders<T> {
Binders::new(
VariableKinds::from_iter(
Interner,
std::iter::once(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)),
),
value,
)
}
pub(crate) fn make_binders_with_count<T: HasInterner<Interner = Interner>>(
db: &dyn HirDatabase,
count: usize,
generics: &Generics,
value: T,
) -> Binders<T> {
let it = generics.iter_id().take(count).map(|id| match id {
Either::Left(_) => None,
Either::Right(id) => Some(db.const_param_ty(id)),
});
crate::make_type_and_const_binders(it, value)
}
pub(crate) fn make_binders<T: HasInterner<Interner = Interner>>(
db: &dyn HirDatabase,
generics: &Generics,
value: T,
) -> Binders<T> {
make_binders_with_count(db, usize::MAX, generics, value)
}
// FIXME: get rid of this, just replace it by FnPointer
/// A function signature as seen by type inference: Several parameter types and
/// one return type.
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct CallableSig {
params_and_return: Arc<[Ty]>,
is_varargs: bool,
safety: Safety,
abi: FnAbi,
}
has_interner!(CallableSig);
#[derive(Debug, Copy, Clone, Eq)]
pub enum FnAbi {
Aapcs,
AapcsUnwind,
AmdgpuKernel,
AvrInterrupt,
AvrNonBlockingInterrupt,
C,
CCmseNonsecureCall,
CDecl,
CDeclUnwind,
CUnwind,
Efiapi,
Fastcall,
FastcallUnwind,
Msp430Interrupt,
PlatformIntrinsic,
PtxKernel,
RiscvInterruptM,
RiscvInterruptS,
Rust,
RustCall,
RustCold,
RustIntrinsic,
Stdcall,
StdcallUnwind,
System,
SystemUnwind,
Sysv64,
Sysv64Unwind,
Thiscall,
ThiscallUnwind,
Unadjusted,
Vectorcall,
VectorcallUnwind,
Wasm,
Win64,
Win64Unwind,
X86Interrupt,
Unknown,
}
impl PartialEq for FnAbi {
fn eq(&self, _other: &Self) -> bool {
// FIXME: Proper equality breaks `coercion::two_closures_lub` test
true
}
}
impl Hash for FnAbi {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
// Required because of the FIXME above and due to us implementing `Eq`, without this
// we would break the `Hash` + `Eq` contract
core::mem::discriminant(&Self::Unknown).hash(state);
}
}
impl FnAbi {
#[allow(clippy::should_implement_trait)]
pub fn from_str(s: &str) -> FnAbi {
match s {
"aapcs-unwind" => FnAbi::AapcsUnwind,
"aapcs" => FnAbi::Aapcs,
"amdgpu-kernel" => FnAbi::AmdgpuKernel,
"avr-interrupt" => FnAbi::AvrInterrupt,
"avr-non-blocking-interrupt" => FnAbi::AvrNonBlockingInterrupt,
"C-cmse-nonsecure-call" => FnAbi::CCmseNonsecureCall,
"C-unwind" => FnAbi::CUnwind,
"C" => FnAbi::C,
"cdecl-unwind" => FnAbi::CDeclUnwind,
"cdecl" => FnAbi::CDecl,
"efiapi" => FnAbi::Efiapi,
"fastcall-unwind" => FnAbi::FastcallUnwind,
"fastcall" => FnAbi::Fastcall,
"msp430-interrupt" => FnAbi::Msp430Interrupt,
"platform-intrinsic" => FnAbi::PlatformIntrinsic,
"ptx-kernel" => FnAbi::PtxKernel,
"riscv-interrupt-m" => FnAbi::RiscvInterruptM,
"riscv-interrupt-s" => FnAbi::RiscvInterruptS,
"rust-call" => FnAbi::RustCall,
"rust-cold" => FnAbi::RustCold,
"rust-intrinsic" => FnAbi::RustIntrinsic,
"Rust" => FnAbi::Rust,
"stdcall-unwind" => FnAbi::StdcallUnwind,
"stdcall" => FnAbi::Stdcall,
"system-unwind" => FnAbi::SystemUnwind,
"system" => FnAbi::System,
"sysv64-unwind" => FnAbi::Sysv64Unwind,
"sysv64" => FnAbi::Sysv64,
"thiscall-unwind" => FnAbi::ThiscallUnwind,
"thiscall" => FnAbi::Thiscall,
"unadjusted" => FnAbi::Unadjusted,
"vectorcall-unwind" => FnAbi::VectorcallUnwind,
"vectorcall" => FnAbi::Vectorcall,
"wasm" => FnAbi::Wasm,
"win64-unwind" => FnAbi::Win64Unwind,
"win64" => FnAbi::Win64,
"x86-interrupt" => FnAbi::X86Interrupt,
_ => FnAbi::Unknown,
}
}
pub fn as_str(self) -> &'static str {
match self {
FnAbi::Aapcs => "aapcs",
FnAbi::AapcsUnwind => "aapcs-unwind",
FnAbi::AmdgpuKernel => "amdgpu-kernel",
FnAbi::AvrInterrupt => "avr-interrupt",
FnAbi::AvrNonBlockingInterrupt => "avr-non-blocking-interrupt",
FnAbi::C => "C",
FnAbi::CCmseNonsecureCall => "C-cmse-nonsecure-call",
FnAbi::CDecl => "C-decl",
FnAbi::CDeclUnwind => "cdecl-unwind",
FnAbi::CUnwind => "C-unwind",
FnAbi::Efiapi => "efiapi",
FnAbi::Fastcall => "fastcall",
FnAbi::FastcallUnwind => "fastcall-unwind",
FnAbi::Msp430Interrupt => "msp430-interrupt",
FnAbi::PlatformIntrinsic => "platform-intrinsic",
FnAbi::PtxKernel => "ptx-kernel",
FnAbi::RiscvInterruptM => "riscv-interrupt-m",
FnAbi::RiscvInterruptS => "riscv-interrupt-s",
FnAbi::Rust => "Rust",
FnAbi::RustCall => "rust-call",
FnAbi::RustCold => "rust-cold",
FnAbi::RustIntrinsic => "rust-intrinsic",
FnAbi::Stdcall => "stdcall",
FnAbi::StdcallUnwind => "stdcall-unwind",
FnAbi::System => "system",
FnAbi::SystemUnwind => "system-unwind",
FnAbi::Sysv64 => "sysv64",
FnAbi::Sysv64Unwind => "sysv64-unwind",
FnAbi::Thiscall => "thiscall",
FnAbi::ThiscallUnwind => "thiscall-unwind",
FnAbi::Unadjusted => "unadjusted",
FnAbi::Vectorcall => "vectorcall",
FnAbi::VectorcallUnwind => "vectorcall-unwind",
FnAbi::Wasm => "wasm",
FnAbi::Win64 => "win64",
FnAbi::Win64Unwind => "win64-unwind",
FnAbi::X86Interrupt => "x86-interrupt",
FnAbi::Unknown => "unknown-abi",
}
}
}
/// A polymorphic function signature.
pub type PolyFnSig = Binders<CallableSig>;
impl CallableSig {
pub fn from_params_and_return(
mut params: Vec<Ty>,
ret: Ty,
is_varargs: bool,
safety: Safety,
abi: FnAbi,
) -> CallableSig {
params.push(ret);
CallableSig { params_and_return: params.into(), is_varargs, safety, abi }
}
pub fn from_def(db: &dyn HirDatabase, def: FnDefId, substs: &Substitution) -> CallableSig {
let callable_def = db.lookup_intern_callable_def(def.into());
let sig = db.callable_item_signature(callable_def);
sig.substitute(Interner, substs)
}
pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
CallableSig {
// FIXME: what to do about lifetime params? -> return PolyFnSig
params_and_return: Arc::from_iter(
fn_ptr
.substitution
.clone()
.shifted_out_to(Interner, DebruijnIndex::ONE)
.expect("unexpected lifetime vars in fn ptr")
.0
.as_slice(Interner)
.iter()
.map(|arg| arg.assert_ty_ref(Interner).clone()),
),
is_varargs: fn_ptr.sig.variadic,
safety: fn_ptr.sig.safety,
abi: fn_ptr.sig.abi,
}
}
pub fn to_fn_ptr(&self) -> FnPointer {
FnPointer {
num_binders: 0,
sig: FnSig { abi: self.abi, safety: self.safety, variadic: self.is_varargs },
substitution: FnSubst(Substitution::from_iter(
Interner,
self.params_and_return.iter().cloned(),
)),
}
}
pub fn params(&self) -> &[Ty] {
&self.params_and_return[0..self.params_and_return.len() - 1]
}
pub fn ret(&self) -> &Ty {
&self.params_and_return[self.params_and_return.len() - 1]
}
}
impl TypeFoldable<Interner> for CallableSig {
fn try_fold_with<E>(
self,
folder: &mut dyn chalk_ir::fold::FallibleTypeFolder<Interner, Error = E>,
outer_binder: DebruijnIndex,
) -> Result<Self, E> {
let vec = self.params_and_return.to_vec();
let folded = vec.try_fold_with(folder, outer_binder)?;
Ok(CallableSig {
params_and_return: folded.into(),
is_varargs: self.is_varargs,
safety: self.safety,
abi: self.abi,
})
}
}
#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
pub enum ImplTraitId {
ReturnTypeImplTrait(hir_def::FunctionId, RpitId),
AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
}
#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub struct ReturnTypeImplTraits {
pub(crate) impl_traits: Arena<ReturnTypeImplTrait>,
}
has_interner!(ReturnTypeImplTraits);
#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub struct ReturnTypeImplTrait {
pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
}
pub type RpitId = Idx<ReturnTypeImplTrait>;
pub fn static_lifetime() -> Lifetime {
LifetimeData::Static.intern(Interner)
}
pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
t: T,
for_ty: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
for_const: impl FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
) -> T {
use chalk_ir::fold::TypeFolder;
#[derive(chalk_derive::FallibleTypeFolder)]
#[has_interner(Interner)]
struct FreeVarFolder<
F1: FnMut(BoundVar, DebruijnIndex) -> Ty,
F2: FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
>(F1, F2);
impl<
F1: FnMut(BoundVar, DebruijnIndex) -> Ty,
F2: FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
> TypeFolder<Interner> for FreeVarFolder<F1, F2>
{
fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner, Error = Self::Error> {
self
}
fn interner(&self) -> Interner {
Interner
}
fn fold_free_var_ty(&mut self, bound_var: BoundVar, outer_binder: DebruijnIndex) -> Ty {
self.0(bound_var, outer_binder)
}
fn fold_free_var_const(
&mut self,
ty: Ty,
bound_var: BoundVar,
outer_binder: DebruijnIndex,
) -> Const {
self.1(ty, bound_var, outer_binder)
}
}
t.fold_with(&mut FreeVarFolder(for_ty, for_const), DebruijnIndex::INNERMOST)
}
pub(crate) fn fold_tys<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
t: T,
mut for_ty: impl FnMut(Ty, DebruijnIndex) -> Ty,
binders: DebruijnIndex,
) -> T {
fold_tys_and_consts(
t,
|x, d| match x {
Either::Left(x) => Either::Left(for_ty(x, d)),
Either::Right(x) => Either::Right(x),
},
binders,
)
}
pub(crate) fn fold_tys_and_consts<T: HasInterner<Interner = Interner> + TypeFoldable<Interner>>(
t: T,
f: impl FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>,
binders: DebruijnIndex,
) -> T {
use chalk_ir::fold::{TypeFolder, TypeSuperFoldable};
#[derive(chalk_derive::FallibleTypeFolder)]
#[has_interner(Interner)]
struct TyFolder<F: FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>>(F);
impl<F: FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>> TypeFolder<Interner>
for TyFolder<F>
{
fn as_dyn(&mut self) -> &mut dyn TypeFolder<Interner, Error = Self::Error> {
self
}
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, FnAbi::RustCall))
}
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()))
}