From e1a6e38767c1e47e5e88a97a9ef5b4547390803c Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Wed, 20 Nov 2019 12:25:02 +0300 Subject: Move Generics to hir_def --- crates/ra_hir_def/src/generics.rs | 163 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 163 insertions(+) create mode 100644 crates/ra_hir_def/src/generics.rs (limited to 'crates/ra_hir_def/src/generics.rs') diff --git a/crates/ra_hir_def/src/generics.rs b/crates/ra_hir_def/src/generics.rs new file mode 100644 index 000000000..4adfc16bb --- /dev/null +++ b/crates/ra_hir_def/src/generics.rs @@ -0,0 +1,163 @@ +//! Many kinds of items or constructs can have generic parameters: functions, +//! structs, impls, traits, etc. This module provides a common HIR for these +//! generic parameters. See also the `Generics` type and the `generics_of` query +//! in rustc. +use std::sync::Arc; + +use hir_expand::name::{self, AsName, Name}; + +use ra_syntax::ast::{self, NameOwner, TypeBoundsOwner, TypeParamsOwner}; + +use crate::{ + db::DefDatabase2, + type_ref::{TypeBound, TypeRef}, + AdtId, AstItemDef, GenericDefId, +}; + +/// Data about a generic parameter (to a function, struct, impl, ...). +#[derive(Clone, PartialEq, Eq, Debug)] +pub struct GenericParam { + // FIXME: give generic params proper IDs + pub idx: u32, + pub name: Name, + pub default: Option, +} + +/// Data about the generic parameters of a function, struct, impl, etc. +#[derive(Clone, PartialEq, Eq, Debug)] +pub struct GenericParams { + pub def: GenericDefId, + pub parent_params: Option>, + pub params: Vec, + pub where_predicates: Vec, +} + +/// A single predicate from a where clause, i.e. `where Type: Trait`. Combined +/// where clauses like `where T: Foo + Bar` are turned into multiple of these. +/// It might still result in multiple actual predicates though, because of +/// associated type bindings like `Iterator`. +#[derive(Clone, PartialEq, Eq, Debug)] +pub struct WherePredicate { + pub type_ref: TypeRef, + pub bound: TypeBound, +} + +impl GenericParams { + pub fn new( + db: &impl DefDatabase2, + def: GenericDefId, + parent_params: Option>, + ) -> GenericParams { + let mut generics = + GenericParams { def, params: Vec::new(), parent_params, where_predicates: Vec::new() }; + let start = generics.parent_params.as_ref().map(|p| p.params.len()).unwrap_or(0) as u32; + // FIXME: add `: Sized` bound for everything except for `Self` in traits + match def { + GenericDefId::FunctionId(it) => generics.fill(&it.source(db).value, start), + GenericDefId::AdtId(AdtId::StructId(it)) => { + generics.fill(&it.0.source(db).value, start) + } + GenericDefId::AdtId(AdtId::UnionId(it)) => generics.fill(&it.0.source(db).value, start), + GenericDefId::AdtId(AdtId::EnumId(it)) => generics.fill(&it.source(db).value, start), + GenericDefId::TraitId(it) => { + // traits get the Self type as an implicit first type parameter + generics.params.push(GenericParam { + idx: start, + name: name::SELF_TYPE, + default: None, + }); + generics.fill(&it.source(db).value, start + 1); + // add super traits as bounds on Self + // i.e., trait Foo: Bar is equivalent to trait Foo where Self: Bar + let self_param = TypeRef::Path(name::SELF_TYPE.into()); + generics.fill_bounds(&it.source(db).value, self_param); + } + GenericDefId::TypeAliasId(it) => generics.fill(&it.source(db).value, start), + // Note that we don't add `Self` here: in `impl`s, `Self` is not a + // type-parameter, but rather is a type-alias for impl's target + // type, so this is handled by the resolver. + GenericDefId::ImplId(it) => generics.fill(&it.source(db).value, start), + GenericDefId::EnumVariantId(_) | GenericDefId::ConstId(_) => {} + } + + generics + } + + fn fill(&mut self, node: &impl TypeParamsOwner, start: u32) { + if let Some(params) = node.type_param_list() { + self.fill_params(params, start) + } + if let Some(where_clause) = node.where_clause() { + self.fill_where_predicates(where_clause); + } + } + + fn fill_bounds(&mut self, node: &impl ast::TypeBoundsOwner, type_ref: TypeRef) { + for bound in + node.type_bound_list().iter().flat_map(|type_bound_list| type_bound_list.bounds()) + { + self.add_where_predicate_from_bound(bound, type_ref.clone()); + } + } + + fn fill_params(&mut self, params: ast::TypeParamList, start: u32) { + for (idx, type_param) in params.type_params().enumerate() { + let name = type_param.name().map_or_else(Name::missing, |it| it.as_name()); + // FIXME: Use `Path::from_src` + let default = type_param.default_type().map(TypeRef::from_ast); + let param = GenericParam { idx: idx as u32 + start, name: name.clone(), default }; + self.params.push(param); + + let type_ref = TypeRef::Path(name.into()); + self.fill_bounds(&type_param, type_ref); + } + } + + fn fill_where_predicates(&mut self, where_clause: ast::WhereClause) { + for pred in where_clause.predicates() { + let type_ref = match pred.type_ref() { + Some(type_ref) => type_ref, + None => continue, + }; + let type_ref = TypeRef::from_ast(type_ref); + for bound in pred.type_bound_list().iter().flat_map(|l| l.bounds()) { + self.add_where_predicate_from_bound(bound, type_ref.clone()); + } + } + } + + fn add_where_predicate_from_bound(&mut self, bound: ast::TypeBound, type_ref: TypeRef) { + if bound.has_question_mark() { + // FIXME: remove this bound + return; + } + let bound = TypeBound::from_ast(bound); + self.where_predicates.push(WherePredicate { type_ref, bound }); + } + + pub fn find_by_name(&self, name: &Name) -> Option<&GenericParam> { + self.params.iter().find(|p| &p.name == name) + } + + pub fn count_parent_params(&self) -> usize { + self.parent_params.as_ref().map(|p| p.count_params_including_parent()).unwrap_or(0) + } + + pub fn count_params_including_parent(&self) -> usize { + let parent_count = self.count_parent_params(); + parent_count + self.params.len() + } + + fn for_each_param<'a>(&'a self, f: &mut impl FnMut(&'a GenericParam)) { + if let Some(parent) = &self.parent_params { + parent.for_each_param(f); + } + self.params.iter().for_each(f); + } + + pub fn params_including_parent(&self) -> Vec<&GenericParam> { + let mut vec = Vec::with_capacity(self.count_params_including_parent()); + self.for_each_param(&mut |p| vec.push(p)); + vec + } +} -- cgit v1.2.3