rust/crates/hir_def/src/resolver.rs
2021-03-22 18:55:51 +01:00

738 lines
25 KiB
Rust

//! Name resolution façade.
use std::sync::Arc;
use base_db::CrateId;
use hir_expand::{
name::{name, Name},
MacroDefId,
};
use rustc_hash::FxHashSet;
use crate::{
body::scope::{ExprScopes, ScopeId},
builtin_type::BuiltinType,
db::DefDatabase,
expr::{ExprId, LabelId, PatId},
generics::GenericParams,
item_scope::{BuiltinShadowMode, BUILTIN_SCOPE},
nameres::DefMap,
path::{ModPath, PathKind},
per_ns::PerNs,
visibility::{RawVisibility, Visibility},
AdtId, AssocContainerId, ConstId, ConstParamId, DefWithBodyId, EnumId, EnumVariantId,
FunctionId, GenericDefId, GenericParamId, HasModule, ImplId, LifetimeParamId, LocalModuleId,
Lookup, ModuleDefId, ModuleId, StaticId, StructId, TraitId, TypeAliasId, TypeParamId,
VariantId,
};
#[derive(Debug, Clone, Default)]
pub struct Resolver {
// FIXME: all usages generally call `.rev`, so maybe reverse once in construction?
scopes: Vec<Scope>,
}
// FIXME how to store these best
#[derive(Debug, Clone)]
struct ModuleItemMap {
def_map: Arc<DefMap>,
module_id: LocalModuleId,
}
#[derive(Debug, Clone)]
struct ExprScope {
owner: DefWithBodyId,
expr_scopes: Arc<ExprScopes>,
scope_id: ScopeId,
}
#[derive(Debug, Clone)]
enum Scope {
/// All the items and imported names of a module
ModuleScope(ModuleItemMap),
/// Brings the generic parameters of an item into scope
GenericParams { def: GenericDefId, params: Arc<GenericParams> },
/// Brings `Self` in `impl` block into scope
ImplDefScope(ImplId),
/// Brings `Self` in enum, struct and union definitions into scope
AdtScope(AdtId),
/// Local bindings
ExprScope(ExprScope),
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum TypeNs {
SelfType(ImplId),
GenericParam(TypeParamId),
AdtId(AdtId),
AdtSelfType(AdtId),
// Yup, enum variants are added to the types ns, but any usage of variant as
// type is an error.
EnumVariantId(EnumVariantId),
TypeAliasId(TypeAliasId),
BuiltinType(BuiltinType),
TraitId(TraitId),
// Module belong to type ns, but the resolver is used when all module paths
// are fully resolved.
// ModuleId(ModuleId)
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum ResolveValueResult {
ValueNs(ValueNs),
Partial(TypeNs, usize),
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum ValueNs {
ImplSelf(ImplId),
LocalBinding(PatId),
FunctionId(FunctionId),
ConstId(ConstId),
StaticId(StaticId),
StructId(StructId),
EnumVariantId(EnumVariantId),
GenericParam(ConstParamId),
}
impl Resolver {
/// Resolve known trait from std, like `std::futures::Future`
pub fn resolve_known_trait(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<TraitId> {
let res = self.resolve_module_path(db, path, BuiltinShadowMode::Other).take_types()?;
match res {
ModuleDefId::TraitId(it) => Some(it),
_ => None,
}
}
/// Resolve known struct from std, like `std::boxed::Box`
pub fn resolve_known_struct(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<StructId> {
let res = self.resolve_module_path(db, path, BuiltinShadowMode::Other).take_types()?;
match res {
ModuleDefId::AdtId(AdtId::StructId(it)) => Some(it),
_ => None,
}
}
/// Resolve known enum from std, like `std::result::Result`
pub fn resolve_known_enum(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<EnumId> {
let res = self.resolve_module_path(db, path, BuiltinShadowMode::Other).take_types()?;
match res {
ModuleDefId::AdtId(AdtId::EnumId(it)) => Some(it),
_ => None,
}
}
fn resolve_module_path(
&self,
db: &dyn DefDatabase,
path: &ModPath,
shadow: BuiltinShadowMode,
) -> PerNs {
let (item_map, module) = match self.module_scope() {
Some(it) => it,
None => return PerNs::none(),
};
let (module_res, segment_index) = item_map.resolve_path(db, module, &path, shadow);
if segment_index.is_some() {
return PerNs::none();
}
module_res
}
pub fn resolve_module_path_in_items(&self, db: &dyn DefDatabase, path: &ModPath) -> PerNs {
self.resolve_module_path(db, path, BuiltinShadowMode::Module)
}
pub fn resolve_module_path_in_trait_items(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<TraitId> {
let (item_map, module) = self.module_scope()?;
let (module_res, ..) = item_map.resolve_path(db, module, &path, BuiltinShadowMode::Module);
match module_res.take_types()? {
ModuleDefId::TraitId(it) => Some(it),
_ => None,
}
}
pub fn resolve_path_in_type_ns(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<(TypeNs, Option<usize>)> {
let first_name = path.segments().first()?;
let skip_to_mod = path.kind != PathKind::Plain;
for scope in self.scopes.iter().rev() {
match scope {
Scope::ExprScope(_) => continue,
Scope::GenericParams { .. } | Scope::ImplDefScope(_) if skip_to_mod => continue,
Scope::GenericParams { params, def } => {
if let Some(local_id) = params.find_type_by_name(first_name) {
let idx = if path.segments().len() == 1 { None } else { Some(1) };
return Some((
TypeNs::GenericParam(TypeParamId { local_id, parent: *def }),
idx,
));
}
}
Scope::ImplDefScope(impl_) => {
if first_name == &name![Self] {
let idx = if path.segments().len() == 1 { None } else { Some(1) };
return Some((TypeNs::SelfType(*impl_), idx));
}
}
Scope::AdtScope(adt) => {
if first_name == &name![Self] {
let idx = if path.segments().len() == 1 { None } else { Some(1) };
return Some((TypeNs::AdtSelfType(*adt), idx));
}
}
Scope::ModuleScope(m) => {
if let Some(res) = m.resolve_path_in_type_ns(db, path) {
return Some(res);
}
}
}
}
None
}
pub fn resolve_path_in_type_ns_fully(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<TypeNs> {
let (res, unresolved) = self.resolve_path_in_type_ns(db, path)?;
if unresolved.is_some() {
return None;
}
Some(res)
}
pub fn resolve_visibility(
&self,
db: &dyn DefDatabase,
visibility: &RawVisibility,
) -> Option<Visibility> {
match visibility {
RawVisibility::Module(_) => {
let (item_map, module) = match self.module_scope() {
Some(it) => it,
None => return None,
};
item_map.resolve_visibility(db, module, visibility)
}
RawVisibility::Public => Some(Visibility::Public),
}
}
pub fn resolve_path_in_value_ns(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<ResolveValueResult> {
let n_segments = path.segments().len();
let tmp = name![self];
let first_name = if path.is_self() { &tmp } else { path.segments().first()? };
let skip_to_mod = path.kind != PathKind::Plain && !path.is_self();
for scope in self.scopes.iter().rev() {
match scope {
Scope::AdtScope(_)
| Scope::ExprScope(_)
| Scope::GenericParams { .. }
| Scope::ImplDefScope(_)
if skip_to_mod =>
{
continue
}
Scope::ExprScope(scope) if n_segments <= 1 => {
let entry = scope
.expr_scopes
.entries(scope.scope_id)
.iter()
.find(|entry| entry.name() == first_name);
if let Some(e) = entry {
return Some(ResolveValueResult::ValueNs(ValueNs::LocalBinding(e.pat())));
}
}
Scope::ExprScope(_) => continue,
Scope::GenericParams { params, def } if n_segments > 1 => {
if let Some(local_id) = params.find_type_by_name(first_name) {
let ty = TypeNs::GenericParam(TypeParamId { local_id, parent: *def });
return Some(ResolveValueResult::Partial(ty, 1));
}
}
Scope::GenericParams { params, def } if n_segments == 1 => {
if let Some(local_id) = params.find_const_by_name(first_name) {
let val = ValueNs::GenericParam(ConstParamId { local_id, parent: *def });
return Some(ResolveValueResult::ValueNs(val));
}
}
Scope::GenericParams { .. } => continue,
Scope::ImplDefScope(impl_) => {
if first_name == &name![Self] {
if n_segments > 1 {
let ty = TypeNs::SelfType(*impl_);
return Some(ResolveValueResult::Partial(ty, 1));
} else {
return Some(ResolveValueResult::ValueNs(ValueNs::ImplSelf(*impl_)));
}
}
}
Scope::AdtScope(adt) => {
if n_segments == 1 {
// bare `Self` doesn't work in the value namespace in a struct/enum definition
continue;
}
if first_name == &name![Self] {
let ty = TypeNs::AdtSelfType(*adt);
return Some(ResolveValueResult::Partial(ty, 1));
}
}
Scope::ModuleScope(m) => {
if let Some(def) = m.resolve_path_in_value_ns(db, path) {
return Some(def);
}
}
}
}
None
}
pub fn resolve_path_in_value_ns_fully(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<ValueNs> {
match self.resolve_path_in_value_ns(db, path)? {
ResolveValueResult::ValueNs(it) => Some(it),
ResolveValueResult::Partial(..) => None,
}
}
pub fn resolve_path_as_macro(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<MacroDefId> {
let (item_map, module) = self.module_scope()?;
item_map.resolve_path(db, module, &path, BuiltinShadowMode::Other).0.take_macros()
}
pub fn process_all_names(&self, db: &dyn DefDatabase, f: &mut dyn FnMut(Name, ScopeDef)) {
for scope in self.scopes.iter().rev() {
scope.process_names(db, f);
}
}
pub fn traits_in_scope(&self, db: &dyn DefDatabase) -> FxHashSet<TraitId> {
let mut traits = FxHashSet::default();
for scope in &self.scopes {
if let Scope::ModuleScope(m) = scope {
if let Some(prelude) = m.def_map.prelude() {
let prelude_def_map = prelude.def_map(db);
traits.extend(prelude_def_map[prelude.local_id].scope.traits());
}
traits.extend(m.def_map[m.module_id].scope.traits());
// Add all traits that are in scope because of the containing DefMaps
m.def_map.with_ancestor_maps(db, m.module_id, &mut |def_map, module| {
if let Some(prelude) = def_map.prelude() {
let prelude_def_map = prelude.def_map(db);
traits.extend(prelude_def_map[prelude.local_id].scope.traits());
}
traits.extend(def_map[module].scope.traits());
None::<()>
});
}
}
traits
}
fn module_scope(&self) -> Option<(&DefMap, LocalModuleId)> {
self.scopes.iter().rev().find_map(|scope| match scope {
Scope::ModuleScope(m) => Some((&*m.def_map, m.module_id)),
_ => None,
})
}
pub fn module(&self) -> Option<ModuleId> {
let (def_map, local_id) = self.module_scope()?;
Some(def_map.module_id(local_id))
}
pub fn krate(&self) -> Option<CrateId> {
// FIXME: can this ever be `None`?
self.module_scope().map(|t| t.0.krate())
}
pub fn where_predicates_in_scope<'a>(
&'a self,
) -> impl Iterator<Item = &'a crate::generics::WherePredicate> + 'a {
self.scopes
.iter()
.rev()
.filter_map(|scope| match scope {
Scope::GenericParams { params, .. } => Some(params),
_ => None,
})
.flat_map(|params| params.where_predicates.iter())
}
pub fn generic_def(&self) -> Option<GenericDefId> {
self.scopes.iter().rev().find_map(|scope| match scope {
Scope::GenericParams { def, .. } => Some(*def),
_ => None,
})
}
pub fn body_owner(&self) -> Option<DefWithBodyId> {
self.scopes.iter().rev().find_map(|scope| match scope {
Scope::ExprScope(it) => Some(it.owner),
_ => None,
})
}
}
pub enum ScopeDef {
PerNs(PerNs),
ImplSelfType(ImplId),
AdtSelfType(AdtId),
GenericParam(GenericParamId),
Local(PatId),
Label(LabelId),
}
impl Scope {
fn process_names(&self, db: &dyn DefDatabase, f: &mut dyn FnMut(Name, ScopeDef)) {
let mut seen = FxHashSet::default();
match self {
Scope::ModuleScope(m) => {
// FIXME: should we provide `self` here?
// f(
// Name::self_param(),
// PerNs::types(Resolution::Def {
// def: m.module.into(),
// }),
// );
m.def_map[m.module_id].scope.entries().for_each(|(name, def)| {
f(name.clone(), ScopeDef::PerNs(def));
});
m.def_map[m.module_id].scope.legacy_macros().for_each(|(name, macro_)| {
let scope = PerNs::macros(macro_, Visibility::Public);
seen.insert((name.clone(), scope));
f(name.clone(), ScopeDef::PerNs(scope));
});
m.def_map.extern_prelude().for_each(|(name, &def)| {
f(name.clone(), ScopeDef::PerNs(PerNs::types(def, Visibility::Public)));
});
BUILTIN_SCOPE.iter().for_each(|(name, &def)| {
f(name.clone(), ScopeDef::PerNs(def));
});
if let Some(prelude) = m.def_map.prelude() {
let prelude_def_map = prelude.def_map(db);
prelude_def_map[prelude.local_id].scope.entries().for_each(|(name, def)| {
let seen_tuple = (name.clone(), def);
if !seen.contains(&seen_tuple) {
f(seen_tuple.0, ScopeDef::PerNs(def));
}
});
}
}
&Scope::GenericParams { ref params, def: parent } => {
for (local_id, param) in params.types.iter() {
if let Some(ref name) = param.name {
let id = TypeParamId { local_id, parent };
f(name.clone(), ScopeDef::GenericParam(id.into()))
}
}
for (local_id, param) in params.consts.iter() {
let id = ConstParamId { local_id, parent };
f(param.name.clone(), ScopeDef::GenericParam(id.into()))
}
for (local_id, param) in params.lifetimes.iter() {
let id = LifetimeParamId { local_id, parent };
f(param.name.clone(), ScopeDef::GenericParam(id.into()))
}
}
Scope::ImplDefScope(i) => {
f(name![Self], ScopeDef::ImplSelfType(*i));
}
Scope::AdtScope(i) => {
f(name![Self], ScopeDef::AdtSelfType(*i));
}
Scope::ExprScope(scope) => {
if let Some((label, name)) = scope.expr_scopes.label(scope.scope_id) {
f(name, ScopeDef::Label(label))
}
scope.expr_scopes.entries(scope.scope_id).iter().for_each(|e| {
f(e.name().clone(), ScopeDef::Local(e.pat()));
});
}
}
}
}
// needs arbitrary_self_types to be a method... or maybe move to the def?
pub fn resolver_for_expr(db: &dyn DefDatabase, owner: DefWithBodyId, expr_id: ExprId) -> Resolver {
let scopes = db.expr_scopes(owner);
resolver_for_scope(db, owner, scopes.scope_for(expr_id))
}
pub fn resolver_for_scope(
db: &dyn DefDatabase,
owner: DefWithBodyId,
scope_id: Option<ScopeId>,
) -> Resolver {
let mut r = owner.resolver(db);
let scopes = db.expr_scopes(owner);
let scope_chain = scopes.scope_chain(scope_id).collect::<Vec<_>>();
for scope in scope_chain.into_iter().rev() {
if let Some(block) = scopes.block(scope) {
if let Some(def_map) = db.block_def_map(block) {
let root = def_map.root();
r = r.push_module_scope(def_map, root);
// FIXME: This adds as many module scopes as there are blocks, but resolving in each
// already traverses all parents, so this is O(n²). I think we could only store the
// innermost module scope instead?
}
}
r = r.push_expr_scope(owner, Arc::clone(&scopes), scope);
}
r
}
impl Resolver {
fn push_scope(mut self, scope: Scope) -> Resolver {
self.scopes.push(scope);
self
}
fn push_generic_params_scope(self, db: &dyn DefDatabase, def: GenericDefId) -> Resolver {
let params = db.generic_params(def);
self.push_scope(Scope::GenericParams { def, params })
}
fn push_impl_def_scope(self, impl_def: ImplId) -> Resolver {
self.push_scope(Scope::ImplDefScope(impl_def))
}
fn push_module_scope(self, def_map: Arc<DefMap>, module_id: LocalModuleId) -> Resolver {
self.push_scope(Scope::ModuleScope(ModuleItemMap { def_map, module_id }))
}
fn push_expr_scope(
self,
owner: DefWithBodyId,
expr_scopes: Arc<ExprScopes>,
scope_id: ScopeId,
) -> Resolver {
self.push_scope(Scope::ExprScope(ExprScope { owner, expr_scopes, scope_id }))
}
}
impl ModuleItemMap {
fn resolve_path_in_value_ns(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<ResolveValueResult> {
let (module_def, idx) =
self.def_map.resolve_path_locally(db, self.module_id, &path, BuiltinShadowMode::Other);
match idx {
None => {
let value = to_value_ns(module_def)?;
Some(ResolveValueResult::ValueNs(value))
}
Some(idx) => {
let ty = match module_def.take_types()? {
ModuleDefId::AdtId(it) => TypeNs::AdtId(it),
ModuleDefId::TraitId(it) => TypeNs::TraitId(it),
ModuleDefId::TypeAliasId(it) => TypeNs::TypeAliasId(it),
ModuleDefId::BuiltinType(it) => TypeNs::BuiltinType(it),
ModuleDefId::ModuleId(_)
| ModuleDefId::FunctionId(_)
| ModuleDefId::EnumVariantId(_)
| ModuleDefId::ConstId(_)
| ModuleDefId::StaticId(_) => return None,
};
Some(ResolveValueResult::Partial(ty, idx))
}
}
}
fn resolve_path_in_type_ns(
&self,
db: &dyn DefDatabase,
path: &ModPath,
) -> Option<(TypeNs, Option<usize>)> {
let (module_def, idx) =
self.def_map.resolve_path_locally(db, self.module_id, &path, BuiltinShadowMode::Other);
let res = to_type_ns(module_def)?;
Some((res, idx))
}
}
fn to_value_ns(per_ns: PerNs) -> Option<ValueNs> {
let res = match per_ns.take_values()? {
ModuleDefId::FunctionId(it) => ValueNs::FunctionId(it),
ModuleDefId::AdtId(AdtId::StructId(it)) => ValueNs::StructId(it),
ModuleDefId::EnumVariantId(it) => ValueNs::EnumVariantId(it),
ModuleDefId::ConstId(it) => ValueNs::ConstId(it),
ModuleDefId::StaticId(it) => ValueNs::StaticId(it),
ModuleDefId::AdtId(AdtId::EnumId(_))
| ModuleDefId::AdtId(AdtId::UnionId(_))
| ModuleDefId::TraitId(_)
| ModuleDefId::TypeAliasId(_)
| ModuleDefId::BuiltinType(_)
| ModuleDefId::ModuleId(_) => return None,
};
Some(res)
}
fn to_type_ns(per_ns: PerNs) -> Option<TypeNs> {
let res = match per_ns.take_types()? {
ModuleDefId::AdtId(it) => TypeNs::AdtId(it),
ModuleDefId::EnumVariantId(it) => TypeNs::EnumVariantId(it),
ModuleDefId::TypeAliasId(it) => TypeNs::TypeAliasId(it),
ModuleDefId::BuiltinType(it) => TypeNs::BuiltinType(it),
ModuleDefId::TraitId(it) => TypeNs::TraitId(it),
ModuleDefId::FunctionId(_)
| ModuleDefId::ConstId(_)
| ModuleDefId::StaticId(_)
| ModuleDefId::ModuleId(_) => return None,
};
Some(res)
}
pub trait HasResolver: Copy {
/// Builds a resolver for type references inside this def.
fn resolver(self, db: &dyn DefDatabase) -> Resolver;
}
impl HasResolver for ModuleId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
let mut def_map = self.def_map(db);
let mut modules = Vec::new();
modules.push((def_map.clone(), self.local_id));
while let Some(parent) = def_map.parent() {
def_map = parent.def_map(db);
modules.push((def_map.clone(), parent.local_id));
}
let mut resolver = Resolver::default();
for (def_map, module) in modules.into_iter().rev() {
resolver = resolver.push_module_scope(def_map, module);
}
resolver
}
}
impl HasResolver for TraitId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
self.lookup(db).container.resolver(db).push_generic_params_scope(db, self.into())
}
}
impl<T: Into<AdtId> + Copy> HasResolver for T {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
let def = self.into();
def.module(db)
.resolver(db)
.push_generic_params_scope(db, def.into())
.push_scope(Scope::AdtScope(def))
}
}
impl HasResolver for FunctionId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
self.lookup(db).container.resolver(db).push_generic_params_scope(db, self.into())
}
}
impl HasResolver for ConstId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
self.lookup(db).container.resolver(db)
}
}
impl HasResolver for StaticId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
self.lookup(db).container.resolver(db)
}
}
impl HasResolver for TypeAliasId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
self.lookup(db).container.resolver(db).push_generic_params_scope(db, self.into())
}
}
impl HasResolver for ImplId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
self.lookup(db)
.container
.resolver(db)
.push_generic_params_scope(db, self.into())
.push_impl_def_scope(self)
}
}
impl HasResolver for DefWithBodyId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
match self {
DefWithBodyId::ConstId(c) => c.resolver(db),
DefWithBodyId::FunctionId(f) => f.resolver(db),
DefWithBodyId::StaticId(s) => s.resolver(db),
}
}
}
impl HasResolver for AssocContainerId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
match self {
AssocContainerId::ModuleId(it) => it.resolver(db),
AssocContainerId::TraitId(it) => it.resolver(db),
AssocContainerId::ImplId(it) => it.resolver(db),
}
}
}
impl HasResolver for GenericDefId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
match self {
GenericDefId::FunctionId(inner) => inner.resolver(db),
GenericDefId::AdtId(adt) => adt.resolver(db),
GenericDefId::TraitId(inner) => inner.resolver(db),
GenericDefId::TypeAliasId(inner) => inner.resolver(db),
GenericDefId::ImplId(inner) => inner.resolver(db),
GenericDefId::EnumVariantId(inner) => inner.parent.resolver(db),
GenericDefId::ConstId(inner) => inner.resolver(db),
}
}
}
impl HasResolver for VariantId {
fn resolver(self, db: &dyn DefDatabase) -> Resolver {
match self {
VariantId::EnumVariantId(it) => it.parent.resolver(db),
VariantId::StructId(it) => it.resolver(db),
VariantId::UnionId(it) => it.resolver(db),
}
}
}