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//! FIXME: write short doc here
use rustc_hash::FxHashMap;
use std::sync::Arc;
use ra_syntax::{ast::AttrsOwner, SmolStr};
use crate::{
db::{AstDatabase, DefDatabase, HirDatabase},
Adt, Crate, Enum, Function, HasSource, ImplBlock, Module, ModuleDef, Static, Struct, Trait,
};
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum LangItemTarget {
Enum(Enum),
Function(Function),
ImplBlock(ImplBlock),
Static(Static),
Struct(Struct),
Trait(Trait),
}
impl LangItemTarget {
pub(crate) fn krate(&self, db: &impl HirDatabase) -> Option<Crate> {
match self {
LangItemTarget::Enum(e) => e.module(db).krate(db),
LangItemTarget::Function(f) => f.module(db).krate(db),
LangItemTarget::ImplBlock(i) => i.module().krate(db),
LangItemTarget::Static(s) => s.module(db).krate(db),
LangItemTarget::Struct(s) => s.module(db).krate(db),
LangItemTarget::Trait(t) => t.module(db).krate(db),
}
}
}
#[derive(Default, Debug, Clone, PartialEq, Eq)]
pub struct LangItems {
items: FxHashMap<SmolStr, LangItemTarget>,
}
impl LangItems {
pub fn target<'a>(&'a self, item: &str) -> Option<&'a LangItemTarget> {
self.items.get(item)
}
/// Salsa query. This will look for lang items in a specific crate.
pub(crate) fn crate_lang_items_query(
db: &(impl DefDatabase + AstDatabase),
krate: Crate,
) -> Arc<LangItems> {
let mut lang_items = LangItems::default();
if let Some(module) = krate.root_module(db) {
lang_items.collect_lang_items_recursive(db, module);
}
Arc::new(lang_items)
}
pub(crate) fn module_lang_items_query(
db: &(impl DefDatabase + AstDatabase),
module: Module,
) -> Option<Arc<LangItems>> {
let mut lang_items = LangItems::default();
lang_items.collect_lang_items(db, module);
if lang_items.items.is_empty() {
None
} else {
Some(Arc::new(lang_items))
}
}
/// Salsa query. Look for a lang item, starting from the specified crate and recursively
/// traversing its dependencies.
pub(crate) fn lang_item_query(
db: &impl DefDatabase,
start_crate: Crate,
item: SmolStr,
) -> Option<LangItemTarget> {
let lang_items = db.crate_lang_items(start_crate);
let start_crate_target = lang_items.items.get(&item);
if let Some(target) = start_crate_target {
Some(*target)
} else {
for dep in start_crate.dependencies(db) {
let dep_crate = dep.krate;
let dep_target = db.lang_item(dep_crate, item.clone());
if dep_target.is_some() {
return dep_target;
}
}
None
}
}
fn collect_lang_items(&mut self, db: &(impl DefDatabase + AstDatabase), module: Module) {
// Look for impl targets
for impl_block in module.impl_blocks(db) {
let src = impl_block.source(db);
if let Some(lang_item_name) = lang_item_name(&src.ast) {
self.items
.entry(lang_item_name)
.or_insert_with(|| LangItemTarget::ImplBlock(impl_block));
}
}
for def in module.declarations(db) {
match def {
ModuleDef::Trait(trait_) => {
self.collect_lang_item(db, trait_, LangItemTarget::Trait)
}
ModuleDef::Adt(Adt::Enum(e)) => self.collect_lang_item(db, e, LangItemTarget::Enum),
ModuleDef::Adt(Adt::Struct(s)) => {
self.collect_lang_item(db, s, LangItemTarget::Struct)
}
ModuleDef::Function(f) => self.collect_lang_item(db, f, LangItemTarget::Function),
ModuleDef::Static(s) => self.collect_lang_item(db, s, LangItemTarget::Static),
_ => {}
}
}
}
fn collect_lang_items_recursive(
&mut self,
db: &(impl DefDatabase + AstDatabase),
module: Module,
) {
if let Some(module_lang_items) = db.module_lang_items(module) {
self.items.extend(module_lang_items.items.iter().map(|(k, v)| (k.clone(), *v)))
}
// Look for lang items in the children
for child in module.children(db) {
self.collect_lang_items_recursive(db, child);
}
}
fn collect_lang_item<T, N>(
&mut self,
db: &(impl DefDatabase + AstDatabase),
item: T,
constructor: fn(T) -> LangItemTarget,
) where
T: Copy + HasSource<Ast = N>,
N: AttrsOwner,
{
let node = item.source(db).ast;
if let Some(lang_item_name) = lang_item_name(&node) {
self.items.entry(lang_item_name).or_insert_with(|| constructor(item));
}
}
}
fn lang_item_name<T: AttrsOwner>(node: &T) -> Option<SmolStr> {
node.attrs()
.filter_map(|a| a.as_simple_key_value())
.filter(|(key, _)| key == "lang")
.map(|(_, val)| val)
.nth(0)
}
|
